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Records |
Links |
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Author |
Erni, R.; Abakumov, A.M.; Rossell, M.D.; Batuk, D.; Tsirlin, A.A.; Nénert, G.; Van Tendeloo, G. |
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Title |
Nanoscale phase separation in perovskites revisited |
Type |
L1 Letter to the editor |
| |
Year |
2014 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
13 |
Issue |
3 |
Pages |
216-217 |
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Keywords |
L1 Letter to the editor; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000331945200002 |
Publication Date |
2014-02-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1476-1122;1476-4660; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
5 |
Open Access |
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Notes |
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Approved  |
Most recent IF: 39.737; 2014 IF: 36.503 |
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Call Number |
UA @ lucian @ c:irua:114579 |
Serial |
2270 |
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| Permanent link to this record |
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Author |
Chen, Y.Z.; Trier, F.; Wijnands, T.; Green, R.J.; Gauquelin, N.; Egoavil, R.; Christensen, D.V.; Koster, G.; Huijben, M.; Bovet, N.; Macke, S.; He, F.; Sutarto, R.; Andersen, N.H.; Sulpizio, J.A.; Honig, M.; Prawiroatmodjo, G.E.D.K.; Jespersen, T.S.; Linderoth, S.; Ilani, S.; Verbeeck, J.; Van Tendeloo, G.; Rijnders, G.; Sawatzky, G.A.; Pryds, N. |
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Title |
Extreme mobility enhancement of two-dimensional electron gases at oxide interfaces by charge-transfer-induced modulation doping |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
14 |
Issue |
14 |
Pages |
801-806 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Two-dimensional electron gases (2DEGs) formed at the interface of insulating complex oxides promise the development of all-oxide electronic devices. These 2DEGs involve many-body interactions that give rise to a variety of physical phenomena such as superconductivity, magnetism, tunable metalinsulator transitions and phase separation. Increasing the mobility of the 2DEG, however, remains a major challenge. Here, we show that the electron mobility is enhanced by more than two orders of magnitude by inserting a single-unit-cell insulating layer of polar La1−xSrxMnO3 (x = 0, 1/8, and 1/3) at the interface between disordered LaAlO3 and crystalline SrTiO3 produced at room temperature. Resonant X-ray spectroscopy and transmission electron microscopy show that the manganite layer undergoes unambiguous electronic reconstruction, leading to modulation doping of such atomically engineered complex oxide heterointerfaces. At low temperatures, the modulation-doped 2DEG exhibits Shubnikovde Haas oscillations and fingerprints of the quantum Hall effect, demonstrating unprecedented high mobility and low electron density. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000358530100022 |
Publication Date |
2015-06-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1476-1122;1476-4660; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
39.737 |
Times cited |
170 |
Open Access |
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| |
Notes |
246102 IFOX; 246791 COUNTATOMS; 278510 VORTEX; Hercules; 312483 ESTEEM2; FWO G004413N; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 39.737; 2015 IF: 36.503 |
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| |
Call Number |
c:irua:127184 c:irua:127184UA @ admin @ c:irua:127184 |
Serial |
1163 |
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| Permanent link to this record |
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Author |
Sathiya, M.; Abakumov, A.M.; Foix, D.; Rousse, G.; Ramesha, K.; Saubanère, M.; Doublet, M. .; Vezin, H.; Laisa, C.P.; Prakash, A.S.; Gonbeau, D.; Van Tendeloo, G.; Tarascon, J.M. |
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Title |
Origin of voltage decay in high-capacity layered oxide electrodes |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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| |
Volume |
14 |
Issue |
14 |
Pages |
230-238 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Although Li-rich layered oxides (Li1+xNiyCozMn1−x−y−zO2 > 250 mAh g−1) are attractive electrode materials providing energy densities more than 15% higher than todays commercial Li-ion cells, they suffer from voltage decay on cycling. To elucidate the origin of this phenomenon, we employ chemical substitution in structurally related Li2RuO3 compounds. Li-rich layered Li2Ru1−yTiyO3 phases with capacities of ~240 mAh g−1 exhibit the characteristic voltage decay on cycling. A combination of transmission electron microscopy and X-ray photoelectron spectroscopy studies reveals that the migration of cations between metal layers and Li layers is an intrinsic feature of the chargedischarge process that increases the trapping of metal ions in interstitial tetrahedral sites. A correlation between these trapped ions and the voltage decay is established by expanding the study to both Li2Ru1−ySnyO3 and Li2RuO3; the slowest decay occurs for the cations with the largest ionic radii. This effect is robust, and the finding provides insights into new chemistry to be explored for developing high-capacity layered electrodes that evade voltage decay. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000348600200024 |
Publication Date |
2014-12-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1476-1122;1476-4660; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
39.737 |
Times cited |
395 |
Open Access |
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Notes |
246791 Countatoms; 312483 Esteem2; esteem2_ta |
Approved |
Most recent IF: 39.737; 2015 IF: 36.503 |
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Call Number |
c:irua:132555 c:irua:132555 |
Serial |
2528 |
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| Permanent link to this record |
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Author |
Zhao, Z.X.; Ma, X.; Cao, S.; Li, Y.Y.; Zeng, C.Y.; Wang, D.X.; Yao, X.; Deng, Z.J.; Zhang, X.P. |
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Title |
Identification of nano-width variants in a fully monoclinic martensitic Ni50Ti50 alloy by scanning electron microscope-based transmission Kikuchi diffraction and improved groupoid structure approach |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Materials Letters |
Abbreviated Journal |
Mater Lett |
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| |
Volume |
281 |
Issue |
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Pages |
128624 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nano-width martensite plates in a fully martensitic Ni50Ti50 alloy are indexed successfully by using the off-axis transmission Kikuchi diffraction in scanning electron microscope (i.e., SEM-based TKD). The data obtained by SEM-TKD are effectively interpreted using an improved approach based on the framework of the theoretical groupoid structure method, where the equivalent variants transformed from the monoclinic variants are introduced to calculate all theoretical axis/angle pairs of rotation, and to formulate a complete list of source martensite to target martensite pairs. Consequently, B19' monoclinic martensite variants in NiTi alloys are identified unambiguously, by using numerical comparison between the experimental and theoretical rotation components, without the reference of retained parent phase. (C) 2020 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000581134200033 |
Publication Date |
2020-09-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0167-577x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
; This work was supported by National Natural Science Foundation of China under Grant Nos. 51571092 and 51401081, and Guangdong Provincial Natural Science Foundation under Grant Nos. 2018B0303110012 and 2017A030313323. ; |
Approved |
Most recent IF: 3; 2020 IF: 2.572 |
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Call Number |
UA @ admin @ c:irua:173509 |
Serial |
6540 |
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| Permanent link to this record |
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Author |
Mallick, S.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Hayward, M.A. |
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Title |
The crystal and defect structures of polar KBiNb2O7 |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
51 |
Issue |
5 |
Pages |
1866-1873 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0. ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately an ~11% chance of being defective – a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000741540300001 |
Publication Date |
2022-01-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
4 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford/Warwick Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE18786). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC (RB 2000148). SM thanks Somerville College for an Oxford Ryniker Lloyd scholarship. PSH and WZ thank the National Science Foundation (DMR-2002319) for support. |
Approved |
Most recent IF: 4 |
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Call Number |
EMAT @ emat @c:irua:185504 |
Serial |
6951 |
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| Permanent link to this record |
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Author |
Gao, C.; Hofer, C.; Jannis, D.; Béché, A.; Verbeeck, J.; Pennycook, T.J. |
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Title |
Overcoming contrast reversals in focused probe ptychography of thick materials: An optimal pipeline for efficiently determining local atomic structure in materials science |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
121 |
Issue |
8 |
Pages |
081906 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Ptychography provides highly efficient imaging in scanning transmission electron microscopy (STEM), but questions have remained over its applicability to strongly scattering samples such as those most commonly seen in materials science. Although contrast reversals can appear in ptychographic phase images as the projected potentials of the sample increase, we show here how these can be easily overcome by a small amount of defocus. The amount of defocus is small enough that it not only can exist naturally when focusing using the annular dark field (ADF) signal but can also be adjusted post acquisition. The ptychographic images of strongly scattering materials are clearer at finite doses than other STEM techniques and can better reveal light atomic columns within heavy lattices. In addition, data for ptychography can now be collected simultaneously with the fastest of ADF scans. This combination of sensitivity and interpretability presents an ideal workflow for materials science. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000844403300006 |
Publication Date |
2022-08-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4 |
Times cited |
9 |
Open Access |
OpenAccess |
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Notes |
European Research Council, 802123-HDEM ; HORIZON EUROPE European Research Council, 823717-ESTEEM3 ; Fonds Wetenschappelijk Onderzoek, G042920N ; Fonds Wetenschappelijk Onderzoek, G042820N ; Horizon 2020 Framework Programme, 101017720 ; Fonds Wetenschappelijk Onderzoek, G013122N ; esteem3reported; esteem3jra |
Approved |
Most recent IF: 4 |
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Call Number |
EMAT @ emat @c:irua:190670 |
Serial |
7120 |
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| Permanent link to this record |
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Author |
Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J. |
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Title |
A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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| |
Volume |
45 |
Issue |
45 |
Pages |
973-979 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations. |
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Address |
Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000367614700018 |
Publication Date |
2015-11-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
6 |
Open Access |
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Notes |
We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2 |
Approved |
Most recent IF: 4.029 |
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| |
Call Number |
c:irua:130408 c:irua:130408 |
Serial |
3998 |
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| Permanent link to this record |
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Author |
Hasanli, N.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Hayward, M.A. |
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Title |
Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5 |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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| |
Volume |
47 |
Issue |
44 |
Pages |
15783-15790 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000450208000019 |
Publication Date |
2018-10-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
4.029 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC. NH acknowledges funding from the “State Programme on Education of Azerbaijani Youth Abroad in 2007-2015” by the Ministry of Education of Azerbaijan. J. V. and N. G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. |
Approved |
Most recent IF: 4.029 |
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Call Number |
EMAT @ emat @c:irua:155771 |
Serial |
5137 |
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| Permanent link to this record |
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Author |
Mikhailova, D.; Reichel, P.; Tsirlin, A.A.; Abakumov, A.M.; Senyshyn, A.; Mogare, K.M.; Schmidt, M.; Kuo, C.Y.; Pao, C.W.; Pi, T.W.; Lee, J.F.; Hu, Z.; Tjeng, L.H.; |
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Title |
Oxygen-driven competition between low-dimensional structures of Sr3CoMO6 and Sr3CoMO7-\delta with M = Ru,Ir |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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| |
Volume |
43 |
Issue |
37 |
Pages |
13883-13891 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We have realized a reversible structure transformation of one-dimensional 1D K4CdCl6-type Sr3CoMO6 with the Co2+/M4+ cation ordering into the two-dimensional 2D double layered Ruddlesden-Popper structure Sr3CoMO7-delta with a random distribution of Co and M (with M = Ru, Ir) upon increasing the partial oxygen pressure. The combined soft and hard X-ray absorption spectroscopy studies show that under transformation, Co and M cations were oxidized to Co3+ and M5+. During oxidation, high-spin Co2+ in Sr3CoMO6 first transforms into high-spin Co3+ in oxygen-deficient Sr3CoMO7-delta, and then further transforms into low-spin Co3+ in fully oxidized Sr3CoMO7 upon further increasing the partial pressure of oxygen. The 1D Sr3CoMO6 compound is magnetically ordered at low temperatures with the magnetic moments lying along the c-axis. Their alignment is parallel for Sr3CoRuO6 and antiparallel for Sr3CoIrO6. The 2D compounds reveal a spin-glass-like behavior related to the random distribution of magnetic cations in the structure. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000342074100009 |
Publication Date |
2014-07-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226;1477-9234; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.029; 2014 IF: 4.197 |
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Call Number |
UA @ lucian @ c:irua:119960 |
Serial |
2545 |
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Author |
Tyablikov, O.A.; Batuk, D.; Tsirlin, A.A.; Batuk, M.; Verchenko, V.Y.; Filimonov, D.S.; Pokholok, K.V.; Sheptyakov, D.V.; Rozova, M.G.; Hadermann, J.; Antipov, E.V.; Abakumov, A.M.; |
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Title |
{110}-Layered B-cation ordering in the anion-deficient perovskite Pb2.4Ba2.6Fe2Sc2TiO13 with the crystallographic shear structure |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
44 |
Issue |
44 |
Pages |
10753-10762 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A novel anion-deficient perovskite-based compound, Pb2.4Ba2.6Fe2Sc2TiO13, was synthesized via the citrate-based route. This compound is an n = 5 member of the A(n)B(n)O(3n-2) homologous series with unit-cell parameters related to the perovskite subcell a(p) approximate to 4.0 angstrom as a(p)root 2 x a(p) x 5a(p)root 2. The crystal structure of Pb2.4Ba2.6Fe2Sc2TiO13 consists of quasi-2D perovskite blocks with a thickness of three octahedral layers separated by the 1/2[110]((1) over bar 01)(p) crystallographic shear (CS) planes, which are parallel to the {110} plane of the perovskite subcell. The CS planes transform the corner-sharing octahedra into chains of edge-sharing distorted tetragonal pyramids. Using a combination of neutron powder diffraction, Fe-57 Mossbauer spectroscopy and atomic resolution electron energy-loss spectroscopy we demonstrate that the B-cations in Pb2.4Ba2.6Fe2Sc2TiO13 are ordered along the {110} perovskite layers with Fe3+ in distorted tetragonal pyramids along the CS planes, Ti4+ preferentially in the central octahedra of the perovskite blocks and Sc3+ in the outer octahedra of the perovskite blocks. Magnetic susceptibility and Mossbauer spectroscopy indicate a broadened magnetic transition around T-N similar to 45 K and the onset of local magnetic fields at low temperatures. The magnetic order is probably reminiscent of that in other A(n)B(n)O(3n-2) homologues, where G-type AFM order within the perovskite blocks has been observed. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000355701000026 |
Publication Date |
2015-01-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226;1477-9234; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.029; 2015 IF: 4.197 |
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Call Number |
c:irua:127001 |
Serial |
22 |
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| Permanent link to this record |
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Author |
Lin, F.; Meng; Kukueva, E.; Altantzis, T.; Mertens, M.; Bals, S.; Cool, P.; Van Doorslaer, S. |
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Title |
Direct-synthesis method towards copper-containing periodic mesoporous organosilicas : detailed investigation of the copper distribution in the material |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
44 |
Issue |
44 |
Pages |
9970-9979 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
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Abstract |
Three-dimensional cubic Fm (3) over barm mesoporous copper-containing ethane-bridged PMO materials have been prepared through a direct-synthesis method at room temperature in the presence of cetyltrimethylammonium bromide as surfactant. The obtained materials have been unambiguously characterized in detail by several sophisticated techniques, including XRD, UV-Vis-Dr, TEM, elemental mapping, continuous- wave and pulsed EPR spectroscopy. The results show that at lower copper loading, the Cu2+ species are well dispersed in the Cu-PMO materials, and mainly exist as mononuclear Cu2+ species. At higher copper loading amount, Cu2+ clusters are observed in the materials, but the distribution of the Cu2+ species is still much better in the Cu-PMO materials prepared through the direct-synthesis method than in a Cu-containing PMO material prepared through an impregnation method. Moreover, the evolution of the copper incorporation during the PMO synthesis has been followed by EPR. The results show that the immobilization of the Cu2+ ion/complex and the formation of the PMO materials are taking place simultaneously. The copper ions are found to be situated on the inner surface of the mesopores of the materials and are accessible, which will be beneficial for the catalytic applications. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000355000700028 |
Publication Date |
2015-04-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226;1477-9234; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
11 |
Open Access |
OpenAccess |
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Notes |
Goa-Bof; 335078 Colouratom; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 4.029; 2015 IF: 4.197 |
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Call Number |
c:irua:126422 |
Serial |
725 |
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| Permanent link to this record |
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Author |
Janssens, K.; van der Snickt, G.; Vanmeert, F.; Legrand, S.; Nuyts, G.; Alfeld, M.; Monico, L.; Anaf, W.; de Nolf, W.; Vermeulen, M.; Verbeeck, J.; De Wael, K. |
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Title |
Non-invasive and non-destructive examination of artistic pigments, paints, and paintings by means of X-Ray methods |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Topics in Current Chemistry |
Abbreviated Journal |
Topics Curr Chem |
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Volume |
374 |
Issue |
374 |
Pages |
81 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic XRF is a variant of the method that is well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi-layers, on the length scale from 1 to 100 μm inside micro-samples taken from paintings. In the context of the characterization of artists pigments subjected to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red spectroscopy and/or Raman microscopy since these methods deliver complementary information of high molecular specificity at more or less the same length scale as the X-ray microprobe techniques. Since microscopic investigation of a relatively limited number of minute paint samples, taken from a given work of art, may not yield representative information about the entire artefact, several methods for macroscopic, non-invasive imaging have recently been developed. Those based on XRF scanning and full-field hyperspectral imaging appear very promising; some recent published results are discussed. |
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Corporate Author |
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Thesis |
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Publisher |
Springer international publishing ag |
Place of Publication |
Cham |
Editor |
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Language |
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Wos |
000391178900006 |
Publication Date |
2016-11-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2365-0869;2364-8961; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.033 |
Times cited |
50 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 4.033 |
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Call Number |
UA @ lucian @ c:irua:139930UA @ admin @ c:irua:139930 |
Serial |
4443 |
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Author |
Wang, C.; Xin, X.; Shu, M.; Huang, S.; Zhang, Y.; Li, X. |
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Title |
Scalable synthesis of one-dimensional Na2Li2Ti6O14 nanofibers as ultrahigh rate capability anodes for lithium-ion batteries |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Inorganic Chemistry Frontiers |
Abbreviated Journal |
Inorg Chem Front |
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Volume |
6 |
Issue |
3 |
Pages |
646-653 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits. Therefore, titanium-based materials have attracted great attention due to their high stability. Here, Na2Li2Ti6O14 nanofibers as anode materials were prepared through a controlled electrospinning method. The Na2Li2Ti6O14 nanofibers presented superior electrochemical performance with high rate capability and long cycle life and can be regarded as a competitive anode candidate for advanced Li-ion batteries. One-dimensional (1D) Na2Li2Ti6O14 nanofibers are able to deliver a capacity of 128.5 mA h g(-1) at 0.5C, and demonstrate superior high-rate charge-discharge capability and cycling stability (the reversible charge capacity is 77.8 mA h g(-1) with a capacity retention of 99.45% at the rate of 10C after 800 cycles). The 1D structure is considered to contribute remarkably to increased rate capability and stability. This simple and scalable method indicates that the Na2Li2Ti6O14 nanofibers have a practical application potential for high performance lithium-ion batteries. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000461092500027 |
Publication Date |
2018-11-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2052-1553 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.036 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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Notes |
; The authors acknowledge financial support from the National Natural Science Foundation of China (21571110), Natural Science Foundation of Zhejiang Province (LY18B010003), and the Ningbo Key Innovation Team (2014B81005), and sponsorship by the K.C. Wong Magna Fund in Ningbo University. ; |
Approved |
Most recent IF: 4.036 |
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Call Number |
UA @ admin @ c:irua:158566 |
Serial |
5258 |
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Author |
García-Sánchez, C.; Philips, D.A.; Gorlé, C. |
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Title |
Quantifying inflow uncertainties for CFD simulations of the flow in downtown Oklahoma City |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Building and environment |
Abbreviated Journal |
Build Environ |
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Volume |
78 |
Issue |
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Pages |
118-129 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Computational Fluid Dynamics (CFD) methods are widely used to investigate wind flow and dispersion in urban environments. Validation with field experiments that represent the full complexity of the problem should be performed to assess the predictive capabilities of the computations. In this context it will be necessary to quantify the effect of uncertainties in simulations of the full-scale problem. The present study aims at quantifying the uncertainty related to the variability in the inflow boundary conditions for Reynolds-averaged Navier-Stokes (RANS) simulations of the flow in downtown Oklahoma City to address validation with the Joint Urban 2003 field measurements. Three uncertain inflow parameters were defined: the wind speed and wind direction at a reference height, and the aerodynamic roughness in the logarithmic velocity inlet profile. An ensemble of 729 RANS simulations were performed to determine the polynomial chaos expansion coefficients that define the response surfaces for the velocity magnitude and direction at 13 field measurement stations, and the results are compared to the experimental data. For the velocity magnitude the mean experimental velocity magnitude is encompassed within the 95% confidence interval for the magnitudes predicted by the Uncertainty Quantification study in all stations. For the velocity direction this holds in 11 out of 13 locations. The study demonstrates the significant potential of applying advanced uncertainty quantification methods to address validation with field measurements and to develop a more realistic approach to the definition of inflow boundary conditions in atmospheric CFD simulations. (C) 2014 Elsevier Ltd. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000338619700013 |
Publication Date |
2014-05-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0360-1323; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.053 |
Times cited |
29 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.053; 2014 IF: 3.341 |
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Call Number |
UA @ lucian @ c:irua:118632 |
Serial |
2742 |
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Author |
Hoang, D.-Q.; Pobedinskas, P.; Nicley, S.S.; Turner, S.; Janssens, S.D.; Van Bael, M.K.; D'Haen, J.; Haenen, K. |
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Title |
Elucidation of the Growth Mechanism of Sputtered 2D Hexagonal Boron Nitride Nanowalls |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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Volume |
16 |
Issue |
7 |
Pages |
3699-3708 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Hexagonal boron nitride nanowall thin films were deposited on Si(100) substrates using a Ar(51%)/N-2(44%)/H-2(5%) gas mixture by unbalanced radio frequency sputtering. The effects of various target-to-substrate distances, substrate temperatures, and substrate tilting angles were investigated. When the substrate is close to the target, hydrogen etching plays a significant role in the film growth, while the effect is negligible for films deposited at a farther distance. The relative quantity of defects was measured by a non-destructive infrared spectroscopy technique that characterized the hydrogen incorporation at dangling nitrogen bonds at defect sites in the deposited films. Despite the films deposited at different substrate tilting angles, the nanowalls of those films were found to consistently grow vertical to the substrate surface, independent of the tilting angle. This implies that chemical processes, rather than physical ones, govern the growth of the nanowalls. The results also reveal that the degree of nanowall crystallization is tunable by varying the growth parameters. Finally, evidence of hydrogen desorption during vacuum annealing is given based on measurements of infrared stretching (E-1u) and bending (A(2u)) modes of the optical phonons, and the H-N vibration mode. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000379456700020 |
Publication Date |
2016-05-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1528-7483 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.055 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.055 |
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Call Number |
UA @ lucian @ c:irua:144690 |
Serial |
4652 |
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Author |
Drijkoningen, S.; Pobedinskas, P.; Korneychuk, S.; Momot, A.; Balasubramaniam, Y.; Van Bael, M.K.; Turner, S.; Verbeeck, J.; Nesladekt, M.; Haenen, K. |
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Title |
On the Origin of Diamond Plates Deposited at Low Temperature |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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Volume |
17 |
Issue |
8 |
Pages |
4306-4314 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crucial requirement for diamond growth at low temperatures, enabling a wide range of new applications, is a high plasma density at a low gas pressure, which leads to a low thermal load onto sensitive substrate materials. While these conditions are not within reach for resonance cavity plasma systems, linear antenna microwave delivery systems allow the deposition of high quality diamond films at temperatures around 400 degrees C and at pressures below 1 mbar. In this work the codeposition of high quality plates and octahedral diamond grains in nanocrystalline films is reported. In contrast to previous reports claiming the need for high temperatures (T >= 850 degrees C), low temperatures (320 degrees C <= T <= 410 degrees C) were sufficient to deposit diamond plate structures. Cross-sectional high resolution transmission electron microscopy studies show that these plates are faulty cubic diamond terminated by large {111} surface facets with very little sp(2) bonded carbon in the grain boundaries. Raman and electron energy loss spectroscopy studies confirm a high diamond quality, above 93% sp(3) carbon content. Three potential mechanisms, that can account for the initial development of the observed plates rich with stacking faults, and are based on the presence of impurities, are proposed. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000407089600031 |
Publication Date |
2017-06-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1528-7483 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.055 |
Times cited |
23 |
Open Access |
Not_Open_Access |
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Notes |
; The Research Foundation – Flanders (FWO) is gratefully acknowledged for financial support in the form of the Postdoctoral Fellowships of P.P. and S.T., contract G.0044.13N “Charge ordering” (S.K., J.V.), the Methusalem “Nano” network, and the Hercules-linear antenna and Raman equipment. ; |
Approved |
Most recent IF: 4.055 |
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Call Number |
UA @ lucian @ c:irua:145735UA @ admin @ c:irua:145735 |
Serial |
4746 |
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Author |
Barreca, D.; Carraro, G.; Maccato, C.; Altantzis, T.; Kaunisto, K.; Gasparotto, A. |
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Title |
Controlled Growth of Supported ZnO Inverted Nanopyramids with Downward Pointing Tips |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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Volume |
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Issue |
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Pages |
acs.cgd.8b00198 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
High purity porous ZnO nanopyramids with controllable properties are grown on their tips on
Si(100) substrates by means of a catalyst-free vapor phase deposition route in a wet oxygen
reaction environment. The system degree of preferential [001] orientation, as well as
nanopyramid size, geometrical shape and density distribution, can be finely tuned by varying the
growth temperature between 300 and 400°C, whereas higher temperatures lead to more compact
systems with a three-dimensional (3D) morphology. A growth mechanism of the obtained ZnO
nanostructures based on a self-catalytic vapor-solid (VS) mode is proposed, in order to explain
the evolution of nanostructure morphologies as a function of the adopted process conditions. The
results obtained by a thorough chemico-physical characterization enable to get an improved
control over the properties of ZnO nanopyramids grown by this technique. Taken together, they
are of noticeable importance not only for fundamental research on ZnO nanomaterials with
controlled nano-organization, but also to tailor ZnO functionalities in view of various potential
applications. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000429508200073 |
Publication Date |
2018-03-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1528-7483 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.055 |
Times cited |
6 |
Open Access |
OpenAccess |
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Notes |
This work has been supported by Padova University ex-60% 2015–2017, P-DiSC #03BIRD2016-UNIPD projects and ACTION post-doc fellowship. T. A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO, Belgium). Thanks are also due to Dr. Rosa Calabrese (Department of Chemical Sciences, Padova University, Italy) and to Dr. T.-P. Ruoko (Department of Chemistry and Bioengineering, Tampere University of Technology, Finland) for skilful technical support. |
Approved |
Most recent IF: 4.055 |
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Call Number |
EMAT @ emat @c:irua:149514 |
Serial |
4904 |
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Author |
Barreca, D.; Gasparotto, A.; Maccato, C.; Tondello, E.; Lebedev, O.I.; Van Tendeloo, G. |
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Title |
CVD of copper oxides from a \beta-diketonate diamine precursor: tailoring the nano-organization |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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Volume |
9 |
Issue |
5 |
Pages |
2470-2480 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A copper(II) hexafluoroacetylacetonate (1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, hfa) adduct with N,N,N¡ä,N¡ä-tetramethylethylenediamine (TMEDA) [Cu(hfa)2¡¤TMEDA] is used for the first time as precursor for the chemical vapor deposition (CVD) of copper oxide nanosystems. The syntheses are carried out under both O2 and O2+H2O reaction atmospheres on Si(100) substrates, at temperatures ranging between 250 and 550 ¡ãC. Subsequently, the interrelations between the preparative conditions and the system composition, nanostructure, and morphology are elucidated by means of complementary analytical techniques [Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron and X-ray excited auger electron spectroscopies (XPS and XE-AES), glancing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM)]. The obtained data revealed a gradual transformation from Cu2O, to Cu2O + CuO, to CuO nanosystems upon increasing the deposition temperature from 250 to 550 ¡ãC under both growth atmospheres. Such a phenomenon was accompanied by a progressive morphological evolution from continuous films to 1D hyperbranched nanostructures. Water vapor introduction in the deposition environment enabled to lower the deposition temperature and resulted in a higher aggregate interconnection, attributed to a higher density of nucleation centers. |
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Corporate Author |
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Place of Publication |
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Wos |
000265892200066 |
Publication Date |
2009-05-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1528-7483;1528-7505; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.055 |
Times cited |
60 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.055; 2009 IF: 4.162 |
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Call Number |
UA @ lucian @ c:irua:77053 |
Serial |
597 |
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Author |
Neira, I.S.; Kolen'ko, Y.V.; Lebedev, O.I.; Van Tendeloo, G.; Gupta, H.S.; Guitián, F.; Yoshimura, M. |
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Title |
An effective morphology control of hydroxyapatite crystals via hydrothermal synthesis |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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| |
Volume |
9 |
Issue |
1 |
Pages |
466-474 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
A facile urea-assisted hydrothermal synthesis and systematic characterization of hydroxyapatite (HA) with calcium nitrate tetrahydrate and diammonium hydrogen phosphate as precursors are reported. The advantage of the proposed technique over previously reported synthetic approaches is the simple but precise control of the HA crystals morphology, which is achieved by employing an intensive, stepwise, and slow thermal decomposition of urea as well as varying initial concentrations of starting reagents. Whereas the plate-, hexagonal prism- and needle-like HA particles preferentially growth along the c-axis, the smaller and fine-plate-like HA crystals demonstrate crystal growth along the (102) and (211) directions, uncommon for HA. Furthermore, it was established that the hydrothermally derived powdered products are phase-pure HA containing CO32− anions in the crystal lattice, that is, AB-type carbonated hydroxyapatite. Transmission electron microscopy (TEM) and electron diffraction (ED) of selected samples reveal that the as-prepared HA crystals are single-crystalline and exhibit a nearly defect-free microstructure. The hardness and elastic modulus of the hexagonal prism-like HA crystals have been investigated on a nanoscale using the nanoindentation technique; the observed trends are discussed. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000262332700073 |
Publication Date |
2008-11-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.055 |
Times cited |
183 |
Open Access |
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|
| |
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.055; 2009 IF: 4.162 |
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| |
Call Number |
UA @ lucian @ c:irua:75740 |
Serial |
853 |
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| Permanent link to this record |
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Author |
Bekermann, D.; Gasparotto, A.; Barreca, D.; Bovo, L.; Devi, A.; Fischer, R.A.; Lebedev, O.I.; Maccato, C.; Tondello, E.; Van Tendeloo, G. |
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| |
Title |
Highly oriented ZnO nanorod arrays by a novel plasma chemical vapor deposition process |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
|
| |
Volume |
10 |
Issue |
4 |
Pages |
2011-2018 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Strongly c-axis oriented ZnO nanorod arrays were grown on Si(100) by plasma enhanced-chemical vapor deposition (PE-CVD) starting from two volatile bis(ketoiminato) zinc(II) compounds Zn[(R′)NC(CH3)═C(H)C(CH3)═O]2, with R′ = -(CH2)xOCH3 (x = 2, 3). A systematic investigation of process parameters enabled us to obtain the selective formation of ZnO nanorods with tailored features, and provided an important insight into their growth mechanism. The morphology, structure, and composition of the synthesized ZnO nanosystems were thoroughly analyzed by field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDXS), glancing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Photoluminescence (PL) measurements were carried out to gain information on the optical properties. Specifically, one-dimensional (1D) ZnO architectures could be grown on Si(100) substrates at temperatures as low as 200−300 °C and radio frequency (RF)-power values of 20 W, provided that a sufficiently high mass supply to the growth surface was maintained. To the best of our knowledge, the present work reports the mildest preparation conditions ever appeared in the literature for the PE-CVD of ZnO nanorods, a key result in view of potential large-scale technological applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000276234500080 |
Publication Date |
2010-03-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
|
| |
ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.055 |
Times cited |
75 |
Open Access |
|
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| |
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.055; 2010 IF: 4.390 |
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| |
Call Number |
UA @ lucian @ c:irua:82311 |
Serial |
1472 |
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| Permanent link to this record |
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Author |
Li, Y.; Tan, H.; Lebedev, O.; Verbeeck, J.; Biermans, E.; Van Tendeloo, G.; Su, B.-L. |
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Title |
Insight into the growth of multiple branched MnOOH nanorods |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
|
| |
Volume |
10 |
Issue |
7 |
Pages |
2969-2976 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Multiple branched manganese oxide hydroxide (MnOOH) nanorods prepared by a hydrothermal process were extensively studied by transmission electron microscopy (TEM). A model of the branch formation is proposed together with a study of the interface structure. The sword-like tip plays a crucial role for the nanorods to form different shapes. Importantly, the branching occurs at an angle of around either 57 degrees or 123 degrees. Specifically, a (111) twin plane can only be formed at the interface with a 123 degrees angle. The interfaces formed with a 57 degrees angle usually contain edge dislocations. Electron energy loss spectroscopy (EELS) demonstrates that the whole crystal has a uniform chemical composition. Interestingly, an epitaxial growth of Mn3O4 at the radial surface was also observed under electron beam irradiation; this is because of the rough purification of the products. The proposed mechanism is expected to shed light on the branched/dendrite nanostructure growth and to provide opportunities for further novel nanomaterial structure growth and design. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000279422700027 |
Publication Date |
2010-06-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1528-7483;1528-7505; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.055 |
Times cited |
41 |
Open Access |
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| |
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 4.055; 2010 IF: 4.390 |
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| |
Call Number |
UA @ lucian @ c:irua:83886UA @ admin @ c:irua:83886 |
Serial |
1672 |
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| Permanent link to this record |
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Author |
Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. |
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Title |
Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Dental Materials |
Abbreviated Journal |
Dent Mater |
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| |
Volume |
32 |
Issue |
32 |
Pages |
e327-e337 |
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| |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
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| |
Abstract |
OBJECTIVE: The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. METHODS: Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n=6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n=10), single edge V-notched beam (SEVNB) fracture toughness (n=8) and Vickers hardness (n=10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n=3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha=0.05). RESULTS: Lowering the alumina content below 0.25wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. SIGNIFICANCE: Three different approaches were compared to improve the translucency of 3Y-TZP ceramics. |
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| |
Address |
KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000389516400003 |
Publication Date |
2016-10-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0109-5641 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.07 |
Times cited |
|
Open Access |
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| |
Notes |
The authors acknowledge the Research Fund of KU Leu- ven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post- doctoral fellowship (PDM/15/153). We thank M. Peumans for the translucency measurements. |
Approved |
Most recent IF: 4.07 |
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| |
Call Number |
EMAT @ emat @ c:irua:136821 |
Serial |
4313 |
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| Permanent link to this record |
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| |
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Author |
Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. |
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| |
Title |
Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Dental materials |
Abbreviated Journal |
Dent Mater |
|
| |
Volume |
32 |
Issue |
12 |
Pages |
E327-E337 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Objective. The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. Methods. Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n = 6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n = 10), single edge V-notched beam (SEVNB) fracture toughness (n = 8) and Vickers hardness (n = 10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n = 3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha = 0.05). Results. Lowering the alumina content below 0.25 wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5 mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2 mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. Significance. Three different approaches were compared to improve the translucency of 3YTZP ceramics. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Copenhagen |
Editor |
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Language |
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Wos |
000389516400003 |
Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0109-5641 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
4.07 |
Times cited |
47 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 4.07 |
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| |
Call Number |
UA @ lucian @ c:irua:140246 |
Serial |
4447 |
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| Permanent link to this record |
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Author |
Zhao, L.; Ding, L.; Soete, J.; Idrissi, H.; Kerckhofs, G.; Simar, A. |
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Title |
Fostering crack deviation via local internal stresses in Al/NiTi composites and its correlation with fracture toughness |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Composites: part A: applied science and manufacturing |
Abbreviated Journal |
Compos Part A-Appl S |
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Volume |
126 |
Issue |
126 |
Pages |
105617 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In the framework of metal matrix composites, a research gap exists regarding tailoring damage mechanisms. The present work aims at developing an Al/NiTi composite incorporating internal stresses in the vicinity of reinforcements. The composite is manufactured by friction stir processing which allows a homogenous NiTi distribution and a good Al/NiTi interface bonding. The internal stresses are introduced via shape memory effect of the embedded NiTi particles. The induced internal strain field is confirmed by digital image correlation and the corresponding stress field is evaluated by finite element simulation. It is found that the damage mechanism is modified in the presence of internal stresses. The consequent enhancement of fracture toughness arises by the fact that the internal stresses foster discrete damages shifted from the fracture ligament line. These damages release the stress concentration at the main crack tip and lead to a deviated crack path when coalescing to accommodate fracture propagation. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000489350600025 |
Publication Date |
2019-09-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1359-835x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.075 |
Times cited |
|
Open Access |
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Notes |
; This research work has been exclusively supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no 716678). The X-ray computed,tomography facilities of the Department of Materials Engineering of the KU Leuven are financed by the Hercules Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). The authors acknowledge Professor F. Delannay from UCLouvain for fruitful discussions. ; |
Approved |
Most recent IF: 4.075 |
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| |
Call Number |
UA @ admin @ c:irua:163706 |
Serial |
5387 |
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| Permanent link to this record |
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Author |
Wei, H.; Hu, Z.-Y.; Xiao, Y.-X.; Tian, G.; Ying, J.; Van Tendeloo, G.; Janiak, C.; Yang, X.-Y.; Su, B.-L. |
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Title |
Control of the interfacial wettability to synthesize highly dispersed PtPd nanocrystals for efficient oxygen reduction reaction |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Chemistry: an Asian journal |
Abbreviated Journal |
Chem-Asian J |
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Volume |
13 |
Issue |
9 |
Pages |
1119-1123 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Highly dispersed PtPd bimetallic nanocrystals with enhanced catalytic activity and stability were prepared by adjusting the interfacial wettability of the reaction solution on a commercial carbon support. This approach holds great promise for the development of high-performance and low-cost catalysts for practical applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000431625200006 |
Publication Date |
2018-03-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1861-4728; 1861-471x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.083 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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Notes |
; This work supported by National Key R&D Program of China (2017YFC1103800), PCSIRT (IRT15R52), NSFC (U1663225, U1662134, 51472190, 51611530672, 21711530705, 51503166), ISTCP (2015DFE52870), HPNSF (2016CFA033, 2017CFB487), and Open Project Program of State Key Laboratory of Petroleum Pollution Control (Grant No. PPC2016007), CNPC Research Institute of Safety and Environmental Technology, SKLPPC. ; |
Approved |
Most recent IF: 4.083 |
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| |
Call Number |
UA @ lucian @ c:irua:151525 |
Serial |
5018 |
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| Permanent link to this record |
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Author |
Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B. |
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Title |
The role of hydrogen during Pt-Ga nanocatalyst formation |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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| |
Volume |
18 |
Issue |
18 |
Pages |
3234-3243 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Hydrogen plays an essential role during the in situ assembly of tailored catalytic materials, and serves as key ingredient in multifarious chemical reactions promoted by these catalysts. Despite intensive debate for several decades, the existence and nature of hydrogen-involved mechanisms – such as hydrogen-spillover, surface migration – have not been unambiguously proven and elucidated up to date. Here, Pt-Ga alloy formation is used as a probe reaction to study the behavior and atomic transport of H and Ga, starting from Pt nanoparticles on hydrotalcite-derived Mg(Ga)(Al)Ox supports. In situ XANES spectroscopy, time-resolved TAP kinetic experiments, HAADF-STEM imaging and EDX mapping are combined to probe Pt, Ga and H in a series of H2 reduction experiments up to 650 degrees C. Mg(Ga)(Al)Ox by itself dissociates hydrogen, but these dissociated hydrogen species do not induce significant reduction of Ga3+ cations in the support. Only in the presence of Pt, partial reduction of Ga3+ into Gadelta+ is observed, suggesting that different reaction mechanisms dominate for Pt- and Mg(Ga)(Al)Ox-dissociated hydrogen species. This partial reduction of Ga3+ is made possible by Pt-dissociated H species which spillover onto non-reducible Mg(Al)Ox or partially reducible Mg(Ga)(Al)Ox and undergo long-range transport over the support surface. Moderately mobile Gadelta+Ox migrates towards Pt clusters, where Gadelta+ is only fully reduced to Ga0 on condition of immediate stabilization inside Pt-Ga alloyed nanoparticles. |
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Address |
Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000369506000106 |
Publication Date |
2016-01-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
1463-9076 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
10 |
Open Access |
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Notes |
This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of beam time at the DUBBLE beam line of the ESRF and travel costs and a postdoctoral fellowship for S.T. The authors acknowledge the assistance from D. Banerjee (XAS campaign 26-01-979) at DUBBLE. E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to V. Bliznuk for acquisition of the TEM images. |
Approved |
Most recent IF: 4.123 |
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| |
Call Number |
c:irua:132315 |
Serial |
4000 |
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| Permanent link to this record |
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Author |
Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. |
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Title |
First-principles analysis of the spectroscopic limited maximum efficiency of photovoltaic absorber layers for CuAu-like chalcogenides and silicon |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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| |
Volume |
18 |
Issue |
18 |
Pages |
20542-20549 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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| |
Abstract |
Chalcopyrite semiconductors are of considerable interest for application as absorber layers in thin-film photovoltaic cells. When growing films of these compounds, however, they are often found to contain CuAu-like domains, a metastable phase of chalcopyrite. It has been reported that for CuInS2, the presence of the CuAu-like phase improves the short circuit current of the chalcopyrite-based photovoltaic cell. We investigate the thermodynamic stability of both phases for a selected list of I-III-VI2 materials using a first-principles density functional theory approach. For the CuIn-VI2 compounds, the difference in formation energy between the chalcopyrite and CuAu-like phase is found to be close to 2 meV per atom, indicating a high likelihood of the presence of CuAu-like domains. Next, we calculate the spectroscopic limited maximum efficiency (SLME) of the CuAu-like phase and compare the results with those of the corresponding chalcopyrite phase. We identify several candidates with a high efficiency, such as CuAu-like CuInS2, for which we obtain an SLME of 29% at a thickness of 500 nm. We observe that the SLME can have values above the Shockley-Queisser (SQ) limit, and show that this can occur because the SQ limit assumes the absorptivity to be a step function, thus overestimating the radiative recombination in the detailed balance approach. This means that it is possible to find higher theoretical efficiencies within this framework simply by calculating the J-V characteristic with an absorption spectrum. Finally, we expand our SLME analysis to indirect band gap absorbers by studying silicon, and find that the SLME quickly overestimates the reverse saturation current of indirect band gap materials, drastically lowering their calculated efficiency. |
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Address |
EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
English |
Wos |
000381428600058 |
Publication Date |
2016-07-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
34 |
Open Access |
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Notes |
We acknowledge financial support of FWO-Vlaanderen through projects G.0150.13N and G.0216.14N and ERA-NET RUS Plus/FWO, Grant G0D6515N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO FWOVlaanderen. |
Approved |
Most recent IF: 4.123 |
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Call Number |
c:irua:135091 |
Serial |
4112 |
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Author |
Calizzi, M.; Venturi, F.; Ponthieu, M.; Cuevas, F.; Morandi, V.; Perkisas, T.; Bals, S.; Pasquini, L. |
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Title |
Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
18 |
Issue |
18 |
Pages |
141-148 |
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Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT) |
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Abstract |
Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 degrees C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2. |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000368755500014 |
Publication Date |
2015-11-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
31 |
Open Access |
Not_Open_Access |
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Notes |
; Part of this work was supported by the COST Action MP1103 “Nanostructured materials for solid-state hydrogen storage”. ; |
Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ lucian @ c:irua:131589 |
Serial |
4184 |
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Author |
Matsubara, M.; Saniz, R.; Partoens, B.; Lamoen, D. |
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Title |
Doping anatase TiO2with group V-b and VI-b transition metal atoms: a hybrid functional first-principles study |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
19 |
Issue |
19 |
Pages |
1945-1952 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We investigate the role of transition metal atoms of group V-b (V, Nb, Ta) and VI-b (Cr, Mo, W) as n- or p-type dopants in anatase TiO$2$ using thermodynamic
principles and density functional theory with the Heyd-Scuseria-Ernzerhof HSE06 hybrid functional. The HSE06 functional provides a realistic value for the band gap, which ensures a correct classification of dopants as shallow or deep donors or acceptors. Defect formation energies and thermodynamic transition levels are calculated taking into account the constraints imposed by the stability of TiO$2$ and the solubility limit of the impurities.
Nb, Ta, W and Mo are identified as shallow donors. Although W provides two electrons, Nb and Ta show a considerable lower formation energy, in particular under O-poor conditions. Mo donates in principle one electron, but under specific conditions can turn into a double donor. V impurities are deep donors and Cr
shows up as an amphoteric defect, thereby acting as an electron trapping center in n-type TiO$_2$ especially under O-rich conditions. A comparison with the available experimental data yields excellent agreement. |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000394426400027 |
Publication Date |
2016-12-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
19 |
Open Access |
OpenAccess |
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Notes |
We gratefully acknowledge financial support from the IWTVlaanderenthrough projects G.0191.08 and G.0150.13, and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation. M. M. acknowledges financial support from the GOA project ‘‘XANES meets ELNES’’ of the University of Antwerp. |
Approved |
Most recent IF: 4.123 |
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Call Number |
EMAT @ emat @ c:irua:140835 |
Serial |
4421 |
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Author |
Saniz, R.; Bekaert, J.; Partoens, B.; Lamoen, D. |
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Title |
Structural and electronic properties of defects at grain boundaries in CuInSe2 |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
19 |
Issue |
19 |
Pages |
14770-14780 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We report on a first-principles study of the structural and electronic properties of a Sigma3 (112) grain boundary model in CuInSe2. The study focuses on a coherent, stoichiometry preserving, cation–Se terminated grain boundary, addressing the properties of the grain boundary as such, as well as the effect
of well known defects in CuInSe2. We show that in spite of its apparent simplicity, such a grain boundary exhibits a very rich phenomenology, providing an explanation for several of the experimentally observed properties of grain boundaries in CuInSe2 thin films. In particular, we show that the combined effect of Cu vacancies and cation antisites can result in the observed Cu depletion with no In enrichment at the grain boundaries. Furthermore, Cu vacancies are unlikely to produce a hole barrier at the grain boundaries, but Na may indeed have such an effect. We find that Na-on-Cu defects will tend to form abundantly at
the grain boundaries, and can provide a mechanism for the carrier depletion and/or type inversion experimentally reported. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000403327200059 |
Publication Date |
2017-05-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
12 |
Open Access |
OpenAccess |
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Notes |
We thank B. Schoeters for his assistance running the GBstudio software. We acknowledge the financial support of FWO-Vlaanderen through project G.0150.13. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by FWO-Vlaanderen and the Flemish Government-department EWI. |
Approved |
Most recent IF: 4.123 |
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Call Number |
EMAT @ emat @ c:irua:143869 |
Serial |
4577 |
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| Permanent link to this record |
