Records |
Author |
Tan, H.; Turner, S.; Yücelen, E.; Verbeeck, J.; Van Tendeloo, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
2D atomic mapping of oxidation states in transition metal oxides by scanning transmission electron microscopy and electron energy-loss spectroscopy |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
107 |
Issue |
10 |
Pages |
107602 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Using a combination of high-angle annular dark-field scanning transmission electron microscopy and atomically resolved electron energy-loss spectroscopy in an aberration-corrected transmission electron microscope we demonstrate the possibility of 2D atom by atom valence mapping in the mixed valence compound Mn3O4. The Mn L2,3 energy-loss near-edge structures from Mn2+ and Mn3+ cation sites are similar to those of MnO and Mn2O3 references. Comparison with simulations shows that even though a local interpretation is valid here, intermixing of the inelastic signal plays a significant role. This type of experiment should be applicable to challenging topics in materials science, such as the investigation of charge ordering or single atom column oxidation states in, e.g., dislocations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000294406600018 |
Publication Date |
2011-09-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
115 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 8.462; 2011 IF: 7.370 |
Call Number |
UA @ lucian @ c:irua:91265 c:irua:91265 c:irua:91265UA @ admin @ c:irua:91265 |
Serial |
5 |
Permanent link to this record |
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|
Author |
Tan, H.; Turner, S.; Yucelen, E.; Verbeeck, J.; Van Tendeloo, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
2D atomic mapping of oxidation states in transition metal oxides by scanning transmission electron microscopy and electron energy-loss spectroscopy : reply |
Type |
Editorial |
Year |
2012 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
108 |
Issue |
25 |
Pages |
259702 |
Keywords |
Editorial; Electron microscopy for materials research (EMAT) |
Abstract |
|
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 |
000305568700038 |
Publication Date |
2012-06-19 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
8.462 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.462; 2012 IF: 7.943 |
Call Number |
UA @ admin @ c:irua:100293 |
Serial |
5370 |
Permanent link to this record |
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|
|
Author |
He, Z.B.; Deng, G.; Tian, H.; Xu, Q.; Van Tendeloo, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
90° Rotation of orbital stripes in bilayer manganite PrCa2Mn2O7 studied by in situ transmission electron microscopy |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
200 |
Issue |
|
Pages |
287-293 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present an in situ transmission electron microscopy study on the half-doped bilayer manganite PrCa2Mn2O7 to reveal the rotation process of the orbital stripes. Between the reported initial and final ordering phases, we identified an intermediate state with two sets of satellite spots to bridge the 90° rotation of the orbital stripes. Furthermore, we determined that the rotation of the orbital stripes does not always occur. Some restricted conditions for the orbital rotation to occur were found and reasons are discussed. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000317158000043 |
Publication Date |
2013-02-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
|
Notes |
Countatoms |
Approved |
Most recent IF: 2.299; 2013 IF: 2.200 |
Call Number |
UA @ lucian @ c:irua:106183 |
Serial |
20 |
Permanent link to this record |
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|
|
Author |
Kim, Y.; Che, F.; Jo, J.W.; Choi, J.; de Arquer, F.P.G.; Voznyy, O.; Sun, B.; Kim, J.; Choi, M.-J.; Quintero-Bermudez, R.; Fan, F.; Tan, C.S.; Bladt, E.; Walters, G.; Proppe, A.H.; Zou, C.; Yuan, H.; Bals, S.; Hofkens, J.; Roeffaers, M.B.J.; Hoogland, S.; Sargent, E.H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
A Facet-Specific Quantum Dot Passivation Strategy for Colloid Management and Efficient Infrared Photovoltaics |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
31 |
Issue |
31 |
Pages |
1805580 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Colloidal nanocrystals combine size- and facet-dependent properties with solution processing. They offer thus a compelling suite of materials for technological applications. Their size- and facet-tunable features are studied in synthesis; however, to exploit their features in optoelectronic devices, it will be essential to translate control over size and facets from the colloid all the way to the film. Larger-diameter colloidal quantum dots (CQDs) offer the attractive possibility of harvesting infrared (IR) solar energy beyond absorption of silicon photovoltaics. These CQDs exhibit facets (nonpolar (100)) undisplayed in small-diameter CQDs; and the materials chemistry of smaller nanocrystals fails consequently to translate to materials for the short-wavelength IR regime. A new colloidal management strategy targeting the passivation of both (100) and (111) facets is demonstrated using distinct choices of cations and anions. The approach leads to narrow-bandgap CQDs with impressive colloidal stability and photoluminescence quantum yield. Photophysical studies confirm a reduction both in Stokes shift (approximate to 47 meV) and Urbach tail (approximate to 29 meV). This approach provides a approximate to 50% increase in the power conversion efficiency of IR photovoltaics compared to controls, and a approximate to 70% external quantum efficiency at their excitonic peak. |
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 |
|
Wos |
000465600000001 |
Publication Date |
2019-03-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
74 |
Open Access |
OpenAccess |
Notes |
; Y.K., F.C., J.W.J., and J.C. contributed equally. This work was supported by King Abdullah University of Science and Technology (KAUST, Office of Sponsored Research (OSR), Award No. OSR-2017-CPF-3325) and Ontario Research Fund-Research Excellence program (ORF7-Ministry of Research and Innovation, Ontario Research Fund-Research Excellence Round 7). E.B. gratefully acknowledges financial support by the Research Foundation-Flanders (FWO Vlaanderen). Y.K. received financial support from the DGIST R&D Programs of the Ministry of Science, ICT & Future Planning of Korea (18-ET-01). M.B.J.R. and J.H. acknowledge financial support from the Research Foundation-Flanders (FWO, grants nr ZW15_09-GOH6316 and G.098319N) and the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04). H.Y. acknowledges the Research Foundation-Flanders (FWO) for a postdoctoral fellowship. The authors thank L. Levina, R. Wolowiec, D. Kopilovic, and E. Palmiano for their technical help over the course of this research. ; |
Approved |
Most recent IF: 19.791 |
Call Number |
UA @ admin @ c:irua:160392 |
Serial |
5239 |
Permanent link to this record |
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|
|
Author |
Verbeeck, J.; Tian, H.; Béché, A. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
A new way of producing electron vortex probes for STEM |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
113 |
Issue |
|
Pages |
83-87 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A spiral holographic aperture is used in the condensor plane of a scanning transmission electron microscope to produce a focussed electron vortex probe carrying a topological charge of either −1, 0 or +1. The spiral aperture design has a major advantage over the previously used forked aperture in that the three beams with topological charge m=−1, 0, and 1 are not side by side in the specimen plane, but rather on top of each other, focussed at different heights. This allows us to have only one selected beam in focus on the sample while the others contribute only to a background signal. In this paper we describe the working principle as well as first experimental results demonstrating atomic resolution HAADF STEM images obtained with electron vortex probes. These results pave the way for atomic resolution magnetic information when combined with electron energy loss spectroscopy. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000300554400002 |
Publication Date |
2011-10-31 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
62 |
Open Access |
|
Notes |
J.V. wants to thank Miles Padgett for suggesting this setup and pointing to the relevant optics literature. Peter Schattschneider is acknowledged for in depth discussions on related topics. J.V acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 46791-COUN-TATOMS and ERC Starting Grant no. 278510 VORTEX. The Qu-Ant-EM microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
Call Number |
UA @ lucian @ c:irua:93624UA @ admin @ c:irua:93624 |
Serial |
2336 |
Permanent link to this record |
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|
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Author |
Palgrave, R.G.; Borisov, P.; Dyer, M.S.; McMitchell, S.R.C.; Darling, G.R.; Claridge, J.B.; Batuk, M.; Tan, H.; Tian, H.; Verbeeck, J.; Hadermann, J.; Rosseinsky, M.J.; |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Artificial construction of the layered Ruddlesden-Popper manganite La2Sr2Mn3O10 by reflection high energy electron diffraction monitored pulsed laser deposition |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
134 |
Issue |
18 |
Pages |
7700-7714 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Pulsed laser deposition has been used to artificially construct the n = 3 Ruddlesden Popper structure La2Sr2Mn3O10 in epitaxial thin film form by sequentially layering La1-xSrxMnO3 and SrO unit cells aided by in situ reflection high energy electron diffraction monitoring. The interval deposition technique was used to promote two-dimensional SrO growth. X-ray diffraction and cross-sectional transmission electron microscopy indicated that the trilayer structure had been formed. A site ordering was found to differ from that expected thermodynamically, with the smaller Sr2+ predominantly on the R site due to kinetic trapping of the deposited cation sequence. A dependence of the out-of-plane lattice parameter on growth pressure was interpreted as changing the oxygen content of the films. Magnetic and transport measurements on fully oxygenated films indicated a frustrated magnetic ground state characterized as a spin glass-like magnetic phase with the glass temperature T-g approximate to 34 K. The magnetic frustration has a clear in-plane (ab) magnetic anisotropy, which is maintained up to temperatures of 150 K. Density functional theory calculations suggest competing antiferromagnetic and ferromagnetic long-range orders, which are proposed as the origin of the low-temperature glassy state. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000303696200029 |
Publication Date |
2012-03-30 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
27 |
Open Access |
|
Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
Call Number |
UA @ lucian @ c:irua:98947UA @ admin @ c:irua:98947 |
Serial |
153 |
Permanent link to this record |
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Author |
Becker, M.; Guzzinati, G.; Béché, A.; Verbeeck, J.; Batelaan, H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Asymmetry and non-dispersivity in the Aharonov-Bohm effect |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
1700 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Decades ago, Aharonov and Bohm showed that electrons are affected by electromagnetic potentials in the absence of forces due to fields. Zeilinger's theorem describes this absence of classical force in quantum terms as the “dispersionless” nature of the Aharonov-Bohm effect. Shelankov predicted the presence of a quantum “force” for the same Aharonov-Bohm physical system as elucidated by Berry. Here, we report an experiment designed to test Shelankov's prediction and we provide a theoretical analysis that is intended to elucidate the relation between Shelankov's prediction and Zeilinger's theorem. The experiment consists of the Aharonov-Bohm physical system; free electrons pass a magnetized nanorod and far-field electron diffraction is observed. The diffraction pattern is asymmetric confirming one of Shelankov's predictions and giving indirect experimental evidence for the presence of a quantum “force”. Our theoretical analysis shows that Zeilinger's theorem and Shelankov's result are both special cases of one theorem. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
|
Wos |
000464338100011 |
Publication Date |
2019-04-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
; H.B. would like to thank Michael Berry for bringing the presence of a quantum “force” to our attention. A.B., G.G. and J.V. acknowledge support from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. G.G. acknowledges support from the Fonds Wetenschappelijk Onderzoek -Vlaanderen (FWO). M.B. and H.B. acknowledge support by the U.S. National Science Foundation under Grant No. 1602755. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:159341 |
Serial |
5241 |
Permanent link to this record |
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|
Author |
Jungbauer, M.; Huehn, S.; Egoavil, R.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.; Moshnyaga, V. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Atomic layer epitaxy of Ruddlesden-Popper SrO(SrTiO3)n films by means of metalorganic aerosol deposition |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
105 |
Issue |
25 |
Pages |
251603 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report an atomic layer epitaxial growth of Ruddlesden-Popper (RP) thin films of SrO(SrTiO3)(n) (n = infinity, 2, 3, 4) by means of metalorganic aerosol deposition (MAD). The films are grown on SrTiO3(001) substrates by means of a sequential deposition of Sr-O/Ti-O-2 atomic monolayers, monitored in-situ by optical ellipsometry. X-ray diffraction and transmission electron microscopy (TEM) reveal the RP structure with n = 2-4 in accordance with the growth recipe. RP defects, observed by TEM in a good correlation with the in-situ ellipsometry, mainly result from the excess of SrO. Being maximal at the film/substrate interface, the SrO excess rapidly decreases and saturates after 5-6 repetitions of the SrO(SrTiO3)(4) block at the level of 2.4%. This identifies the SrTiO3 substrate surface as a source of RP defects under oxidizing conditions within MAD. Advantages and limitations of MAD as a solution-based and vacuum-free chemical deposition route were discussed in comparison with molecular beam epitaxy. (C) 2014 AIP Publishing LLC. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000346914000007 |
Publication Date |
2014-12-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
32 |
Open Access |
|
Notes |
246102 IFOX; 278510 VORTEX; 246791 COUNTATOMS; Hercules; 312483 ESTEEM2; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
Call Number |
UA @ lucian @ c:irua:122830UA @ admin @ c:irua:122830 |
Serial |
172 |
Permanent link to this record |
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Author |
Egoavil, R.; Tan, H.; Verbeeck, J.; Bals, S.; Smith, B.; Kuiper, B.; Rijnders, G.; Koster, G.; Van Tendeloo, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Atomic scale investigation of a PbTiO3/SrRuO3/DyScO3 heterostructure |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
102 |
Issue |
22 |
Pages |
223106-5 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
An epitaxial PbTiO3 thin film grown on self-organized crystalline SrRuO3 nanowires deposited on a DyScO3 substrate with ordered DyO and ScO2 chemical terminations is investigated by transmission electron microscopy. In this PbTiO3/SrRuO3/DyScO3 heterostructure, the SrRuO3 nanowires are assumed to grow on only one type of substrate termination. Here, we report on the structure, morphology, and chemical composition analysis of this heterostructure. Electron energy loss spectroscopy reveals the exact termination sequence in this complex structure. The energy loss near-edge structure of the Ti-L-2,L-3, Sc-L-2,L-3, and O K edges shows intrinsic interfacial electronic reconstruction. Furthermore, PbTiO3 domain walls are observed to start at the end of the nanowires resulting in atomic steps on the film surface. (C) 2013 AIP Publishing LLC. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000320621600070 |
Publication Date |
2013-06-05 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
12 |
Open Access |
|
Notes |
Ifox; Esteem2; Countatoms; Vortex; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
Call Number |
UA @ lucian @ c:irua:109606UA @ admin @ c:irua:109606 |
Serial |
185 |
Permanent link to this record |
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|
|
Author |
Chaves, A.; Azadani, J.G.; Alsalman, H.; da Costa, D.R.; Frisenda, R.; Chaves, A.J.; Song, S.H.; Kim, Y.D.; He, D.; Zhou, J.; Castellanos-Gomez, A.; Peeters, F.M.; Liu, Z.; Hinkle, C.L.; Oh, S.-H.; Ye, P.D.; Koester, S.J.; Lee, Y.H.; Avouris, P.; Wang, X.; Low, T. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Bandgap engineering of two-dimensional semiconductor materials |
Type |
A1 Journal article |
Year |
2020 |
Publication |
npj 2D Materials and Applications |
Abbreviated Journal |
|
Volume |
4 |
Issue |
1 |
Pages |
29-21 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Semiconductors are the basis of many vital technologies such as electronics, computing, communications, optoelectronics, and sensing. Modern semiconductor technology can trace its origins to the invention of the point contact transistor in 1947. This demonstration paved the way for the development of discrete and integrated semiconductor devices and circuits that has helped to build a modern society where semiconductors are ubiquitous components of everyday life. A key property that determines the semiconductor electrical and optical properties is the bandgap. Beyond graphene, recently discovered two-dimensional (2D) materials possess semiconducting bandgaps ranging from the terahertz and mid-infrared in bilayer graphene and black phosphorus, visible in transition metal dichalcogenides, to the ultraviolet in hexagonal boron nitride. In particular, these 2D materials were demonstrated to exhibit highly tunable bandgaps, achieved via the control of layers number, heterostructuring, strain engineering, chemical doping, alloying, intercalation, substrate engineering, as well as an external electric field. We provide a review of the basic physical principles of these various techniques on the engineering of quasi-particle and optical bandgaps, their bandgap tunability, potentials and limitations in practical realization in future 2D device technologies. |
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 |
000565588500001 |
Publication Date |
2020-08-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2397-7132 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
604 |
Open Access |
|
Notes |
; Discussions and interactions with D.R. Reichman, F. Tavazza, N.M.R. Peres, and K. Choudhary are gratefully acknowledged. A.C. acknowledges financial support by CNPq, through the PRONEX/FUNCAP and PQ programs. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 755655, ERCStG 2017 project 2D-TOPSENSE). Computational support from the Minnesota Supercomputing Institute (MSI) and EU Graphene Flagship funding (Grant Graphene Core 2, 785219) is acknowledged. R.F. acknowledges support from the Netherlands Organization for Scientific Research (NWO) through the research program Rubicon with project number 680-50-1515. D.H., J.Z., and X.W. acknowledge support by National Natural Science Foundation of China 61734003, 61521001, 61704073, 51861145202, and 61851401, and National Key Basic Research Program of China 2015CB921600 and 2018YFB2200500. J.Z. and Z.L. acknowledge support by RG7/18, MOE2017-T2-2-136, MOE2018-T3-1-002, and A*Star QTE program. S.H.S. and Y.H.L. acknowledge the support from IBS-R011-D1. Y.D.K. is supported by Samsung Research and Incubation Funding Center of Samsung Electronics under Project Number SRFC-TB1803-04. S.J.K acknowledges financial support by the National Science Foundation (NSF), under award DMR-1921629. T.L. and J.G.A. acknowledge funding support from NSF/DMREF under Grant Agreement No. 1921629. S.-H.O. acknowledges support from the U.S. National Science Foundation (NSF ECCS 1809723) and Samsung Global Research Outreach (GRO) project. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:172069 |
Serial |
6459 |
Permanent link to this record |
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|
|
Author |
Molina, L.; Tan, H.; Biermans, E.; Batenburg, K.J.; Verbeeck, J.; Bals, S.; Van Tendeloo, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Barrier efficiency of sponge-like La2Zr2O7 buffer layers for YBCO-coated conductors |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
24 |
Issue |
6 |
Pages |
065019-065019,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
Solution derived La2Zr2O7 films have drawn much attention for potential applications as thermal barriers or low-cost buffer layers for coated conductor technology. Annealing and coating parameters strongly affect the microstructure of La2Zr2O7, but different film processing methods can yield similar microstructural features such as nanovoids and nanometer-sized La2Zr2O7 grains. Nanoporosity is a typical feature found in such films and the implications for the functionality of the films are investigated by a combination of scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and quantitative electron tomography. Chemical solution based La2Zr2O7 films deposited on flexible Ni5 at.%W substrates with a {100}lang001rang biaxial texture were prepared for an in-depth characterization. A sponge-like structure composed of nanometer-sized voids is revealed by high-angle annular dark-field scanning transmission electron microscopy in combination with electron tomography. A three-dimensional quantification of nanovoids in the La2Zr2O7 film is obtained on a local scale. Mostly non-interconnected highly faceted nanovoids compromise more than one-fifth of the investigated sample volume. The diffusion barrier efficiency of a 170 nm thick La2Zr2O7 film is investigated by STEM-EELS, yielding a 1.8 ± 0.2 nm oxide layer beyond which no significant nickel diffusion can be detected and intermixing is observed. This is of particular significance for the functionality of YBa2Cu3O7 − δ coated conductor architectures based on solution derived La2Zr2O7 films as diffusion barriers. |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000290472900021 |
Publication Date |
2011-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
31 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 2.878; 2011 IF: 2.662 |
Call Number |
UA @ lucian @ c:irua:88639UA @ admin @ c:irua:88639 |
Serial |
221 |
Permanent link to this record |
|
|
|
Author |
Zhang, G.; Huang, S.; Chaves, A.; Yan, H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Black phosphorus as tunable Van der Waals quantum wells with high optical quality |
Type |
A1 Journal article |
Year |
2023 |
Publication |
ACS nano |
Abbreviated Journal |
|
Volume |
17 |
Issue |
6 |
Pages |
6073-6080 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Van der Waals quantum wells, naturally formed in two-dimensional layered materials with nanoscale thickness, possess many inherent advantages over conventional molecular beam epitaxy grown counterparts, and could bring up intriguing physics and applications. However, optical transitions originated from the series of quantized states in these emerging quantum wells are still elusive. Here, we show that multilayer black phosphorus appears to be an excellent candidate for van der Waals quantum wells with well-defined subbands and high optical quality. Using infrared absorption spectroscopy, we probe subband structures of multilayer black phosphorus with tens of atomic layers, revealing clear signatures for optical transitions with subband index as high as 10, far from what was attainable previously. Surprisingly, in addition to allowed transitions, an unexpected series of “forbidden” transitions is also evidently observed, which enables us to determine energy spacings separately for conduction and valence subbands. Furthermore, the linear tunability of subband spacings by temperature and strain is demonstrated. Our results are expected to facilitate potential applications for infrared optoelectronics based on tunable van der Waals quantum wells. |
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 |
|
Wos |
000953463300001 |
Publication Date |
2023-03-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 17.1; 2023 IF: 13.942 |
Call Number |
UA @ admin @ c:irua:196100 |
Serial |
7565 |
Permanent link to this record |
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|
|
Author |
Ramachandran, R.K.; Filez, M.; Solano, E.; Poelman, H.; Minjauw, M.M.; Van Daele, M.; Feng, J.-Y.; La Porta, A.; Altantzis, T.; Fonda, E.; Coati, A.; Garreau, Y.; Bals, S.; Marin, G.B.; Detavernier, C.; Dendooven, J. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Chemical and Structural Configuration of Pt Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
31 |
Issue |
31 |
Pages |
9673-9683 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
Abstract |
Pt doped semiconducting metal oxides and Pt metal clusters embedded in an oxide matrix are of interest for applications such as catalysis and gas sensing, energy storage and memory devices. Accurate tuning of the dopant level is crucial for adjusting the properties of these materials. Here, a novel atomic layer deposition (ALD) based method for doping Pt into In2O3 in specific, and metals in metal oxides in general, is demonstrated. This approach combines alternating exposures of Pt and In2O3 ALD processes in a single ‘supercycle’, followed by supercycle repetition leading to multilayered nanocomposites. The atomic level control of ALD and its conformal nature make the method suitable for accurate dopant control even on high surface area supports. Oxidation state, local structural environment and crystalline phase of the embedded Pt dopants were obtained by means of X-ray characterization methods and high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In addition, this approach allows characterization of the nucleation stages of metal ALD processes, by stacking those states multiple times in an oxide matrix. Regardless of experimental conditions, a few Pt ALD cycles leads to the formation of oxidized Pt species due to their highly dispersed nature, as proven by X-ray absorption spectroscopy (XAS). Grazing-incidence small-angle X-ray scattering (GISAXS) and highresolution scanning transmission electron microscopy, combined with energy dispersive X-ray spectroscopy (HR-STEM/EDXS) show that Pt is evenly distributed in the In2O3 metal oxide matrix without the formation of clusters. For a larger number of Pt ALD
cycles, typ. > 10, the oxidation state gradually evolves towards fully metallic, and metallic Pt clusters are obtained within the In2O3 metal oxide matrix. This work reveals how tuning of the ALD supercycle approach for Pt doping allows controlled engineering of the Pt compositional and structural configuration within a metal oxide matrix. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000502418000010 |
Publication Date |
2019-11-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
6 |
Open Access |
OpenAccess |
Notes |
This research was supported by the Flemish Research Foundation (FWO-Vlaanderen), the Flemish Government (Long term structural funding – Methusalem funding and Medium scale research infrastructure funding-Hercules funding), the Special Research Fund BOF of Ghent University (GOA 01G01513) and the CALIPSO Trans National Access Program funded by the European Commission in supplying financing of travel costs. We are grateful to the SIXS and SAMBA-SOLEIL staff for smoothly running the beamline facilities. J.D. and R.K.R. are postdoctoral fellows of the FWO. |
Approved |
Most recent IF: 9.466 |
Call Number |
EMAT @ emat @c:irua:164056 |
Serial |
5380 |
Permanent link to this record |
|
|
|
Author |
Dharanipragada, N.V.R.A.; Meledina, M.; Galvita, V.V.; Poelman, H.; Turner, S.; Van Tendeloo, G.; Detavernier, C.; Marin, G.B. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Deactivation study of Fe2O3-CeO2 during redox cycles for CO production from CO2 |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Industrial and engineering chemistry research |
Abbreviated Journal |
Ind Eng Chem Res |
Volume |
55 |
Issue |
55 |
Pages |
5911-5922 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Deactivation was investigated in Fe2O3-CeO2 oxygen storage materials during repeated H-2-reduction and CO2-reoxidation. In situ XRD, XAS, and TEM were used to identify phases, crystallite sizes, and morphological changes upon cycling operation. The effect of redox cycling was investigated both in Fe-rich (80 wt % Fe2O3-CeO2) and Ce-rich (10 wt %Fe2O3-CeO2) materials. The former consisted of 100 nm Fe2O3 particles decorated with 5-10 nm Ce1-xFexO2-x. The latter presented CeO2 with incorporated Fe, i.e. a solid solution of Ce1-xFexO2-x, as the main oxygen carrier. By modeling the EXAFS Ce-K signal for as-prepared 10 wt %Fe2O3-CeO2, the amount of Fe in CeO2 was determined as 21 mol %, corresponding to 86% of the total iron content. Sintering and solid solid transformations, the latter including both new phase formation and element segregation, were identified as deactivation pathways upon redox cycling. In Ce-rich material, perovskite (CeFeO3) was identified by XRD. This phase remained inert during reduction and reoxidation, resulting in an overall lower oxygen storage capacity. Further, Fe segregated from the solid solution, thereby decreasing its reducibility. In addition, an increase in crystallite size occurred for all phases. In Fe-rich material, sintering is the main deactivation pathway, although Fe segregation from the solid solution and perovskite formation cannot be excluded. |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000376825300013 |
Publication Date |
2016-04-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0888-5885; 1520-5045 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
26 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ lucian @ c:irua:134214 |
Serial |
4158 |
Permanent link to this record |
|
|
|
Author |
Monico, L.; Janssens, K.; Miliani, C.; Brunetti, B.G.; Vagnini, M.; Vanmeert, F.; Falkenberg, G.; Abakumov, A.; Lu, Y.; Tian, H.; Verbeeck, J.; Radepont, M.; Cotte, M.; Hendriks, E.; Geldof, M.; van der Loeff, L.; Salvant, J.; Menu, M.; |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 3 : synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
85 |
Issue |
2 |
Pages |
860-867 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO4 and PbCr1-xSxO4, that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO4 and PbCr1-xSxO4, permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Goghs Portrait of Gauguin (Van Gogh Museum, Amsterdam). |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000313668400031 |
Publication Date |
2012-10-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
79 |
Open Access |
|
Notes |
Goa; Fwo |
Approved |
Most recent IF: 6.32; 2013 IF: 5.825 |
Call Number |
UA @ lucian @ c:irua:108707UA @ admin @ c:irua:108707 |
Serial |
631 |
Permanent link to this record |
|
|
|
Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
83 |
Issue |
4 |
Pages |
1214-1223 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000287176900011 |
Publication Date |
2011-02-14 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
113 |
Open Access |
|
Notes |
Iuap; Fwo |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
Call Number |
UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 |
Serial |
632 |
Permanent link to this record |
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|
|
Author |
Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Filonenko, V.P.; Gonnissen, J.; Tan, H.; Verbeeck, J.; Gemmi, M.; Antipov, E.V.; Rosner, H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Direct space structure solution from precession electron diffraction data: resolving heavy and light scatterers in Pb13Mn9O25 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
110 |
Issue |
7 |
Pages |
881-890 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The crystal structure of a novel compound Pb13Mn9O25 has been determined through a direct space structure solution with a Monte-Carlo-based global optimization using precession electron diffraction data (a=14.177(3) Å, c=3.9320(7) Å, SG P4/m, RF=0.239) and compositional information obtained from energy dispersive X-ray analysis and electron energy loss spectroscopy. This allowed to obtain a reliable structural model even despite the simultaneous presence of both heavy (Pb) and light (O) scattering elements and to validate the accuracy of the electron diffraction-based structure refinement. This provides an important benchmark for further studies of complex structural problems with electron diffraction techniques. Pb13Mn9O25 has an anion- and cation-deficient perovskite-based structure with the A-positions filled by the Pb atoms and 9/13 of the B positions filled by the Mn atoms in an ordered manner. MnO6 octahedra and MnO5 tetragonal pyramids form a network by sharing common corners. Tunnels are formed in the network due to an ordered arrangement of vacancies at the B-sublattice. These tunnels provide sufficient space for localization of the lone 6s2 electron pairs of the Pb2+ cations, suggested as the driving force for the structural difference between Pb13Mn9O25 and the manganites of alkali-earth elements with similar compositions. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000280050900023 |
Publication Date |
2010-04-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
24 |
Open Access |
|
Notes |
Fwo; Bof; Esteem |
Approved |
Most recent IF: 2.843; 2010 IF: 2.063 |
Call Number |
UA @ lucian @ c:irua:84085UA @ admin @ c:irua:84085 |
Serial |
721 |
Permanent link to this record |
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|
|
Author |
Samal, D.; Tan, H.; Takamura, Y.; Siemons, W.; Verbeeck, J.; Van Tendeloo, G.; Arenholz, E.; Jenkins, C.A.; Rijnders, G.; Koster, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Direct structural and spectroscopic investigation of ultrathin films of tetragonal CuO: Six-fold coordinated copper |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
105 |
Issue |
1 |
Pages |
17003-17005 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Unlike other 3d transition metal monoxides (MnO, FeO, CoO, and NiO), CuO is found in a low-symmetry distorted monoclinic structure rather than the rocksalt structure. We report here of the growth of ultrathin CuO films on SrTiO3 substrates; scanning transmission electron microscopy was used to show the stabilization of a tetragonal rocksalt structure with an elongated c-axis such that c/a similar to 1.34 and the Cu-O-Cu bond angle similar to 180 degrees, pointing to metastable six-fold coordinated Cu. X-ray absorption spectroscopy demonstrates that the hole at the Cu site for the CuO is localized in 3d(x2-y2) orbital unlike the well-studied monoclinic CuO phase. The experimental confirmation of the tetragonal structure of CuO opens up new avenues to explore electronic and magnetic properties of six-fold coordinated Cu. Copyright (C) EPLA, 2014 |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Paris |
Editor |
|
Language |
|
Wos |
000331197100015 |
Publication Date |
2014-01-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
15 |
Open Access |
|
Notes |
This work was carried out with financial support from the AFOSR and EOARD projects (project No.: FA8655-10-1-3077) and also supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC grant No. 246791 – COUNTATOMS, ERC Starting Grant 278510 VORTEX, Grant No. NMP3-LA-2010-246102 IFOX and an Integrated Infrastructure Initiative, reference No. 312483-ESTEEM2. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. Advanced Light Source is supported by the Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. YT acknowledges support from the National Science Foundation (DMR-0747896). WS was supported by the US DOE, Basic Energy Sciences, Materials Sciences and Engineering Division. ECASJO_; |
Approved |
Most recent IF: 1.957; 2014 IF: 2.095 |
Call Number |
UA @ lucian @ c:irua:115806UA @ admin @ c:irua:115806 |
Serial |
722 |
Permanent link to this record |
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|
|
Author |
Du, K.; Guo, L.; Peng, J.; Chen, X.; Zhou, Z.-N.; Zhang, Y.; Zheng, T.; Liang, Y.-P.; Lu, J.-P.; Ni, Z.-H.; Wang, S.-S.; Van Tendeloo, G.; Zhang, Z.; Dong, S.; Tian, H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Direct visualization of irreducible ferrielectricity in crystals |
Type |
A1 Journal article |
Year |
2020 |
Publication |
npj Quantum Materials |
Abbreviated Journal |
|
Volume |
5 |
Issue |
1 |
Pages |
49-7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In solids, charge polarity can one-to-one correspond to spin polarity phenomenologically, e.g., ferroelectricity/ferromagnetism, antiferroelectricity/antiferromagnetism, and even dipole-vortex/magnetic-vortex, but ferrielectricity/ferrimagnetism kept telling a disparate story in microscopic level. Since the definition of a charge dipole involves more than one ion, there may be multiple choices for a dipole unit, which makes most ferrielectric orders equivalent to ferroelectric ones, i.e., this ferrielectricity is not necessary to be a real independent branch of polarity. In this work, by using the spherical aberration-corrected scanning transmission electron microscope, we visualize a nontrivial ferrielectric structural evolution in BaFe2Se3, in which the development of two polar sub-lattices is out-of-sync, for which we term it as irreducible ferrielectricity. Such irreducible ferrielectricity leads to a non-monotonic behavior for the temperature-dependent polarization, and even a compensation point in the ordered state. Our finding unambiguously distinguishes ferrielectrics from ferroelectrics in solids. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000551499400001 |
Publication Date |
2020-07-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2397-4648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
; We acknowledge the National Natural Science Foundation of China (Grant Nos. 11834002, 11674055, and 11234011), National Key R&D Program of China 2017YFB0703100, and the 111 Project (Grant No. B16042). K.D. acknowledges the China Scholarship Council (CSC, No.201806320230) for sponsorship and 2019 Zhejiang University Academic Award for Outstanding Doctoral Candidates. We thank Prof. Fang Lin for providing guidance on calculating atoms position and Dr. Andrew Studer for performing neutron powder diffraction. We thank Prof. Sang-Wook Cheong, Prof. Zhigao Sheng, Prof. Qianghua Wang, Prof. Meng Wang, Prof. Renkui Zheng, Prof. Takuya Aoyama, Dr. Zhibo Yan, and Dr. Meifeng Liu for valuable discussion and/or technical help during measurements. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:171225 |
Serial |
6486 |
Permanent link to this record |
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|
|
Author |
Zhou, Y.; Che, F.; Liu, M.; Zou, C.; Liang, Z.; De Luna, P.; Yuan, H.; Li, J.; Wang, Z.; Xie, H.; Li, H.; Chen, P.; Bladt, E.; Quintero-Bermudez, R.; Sham, T.-K.; Bals, S.; Hofkens, J.; Sinton, D.; Chen, G.; Sargent, E.H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Dopant-induced electron localization drives CO2 reduction to C2 hydrocarbons |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
Volume |
10 |
Issue |
10 |
Pages |
974-980 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The electrochemical reduction of CO2 to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO2 conversion to C-2 products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C-2 products. Here, we use boron to tune the ratio of Cu delta+ to Cu-0 active sites and improve both stability and C-2-product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C-2 products. We report experimentally a C-2 Faradaic efficiency of 79 +/- 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of similar to 40 hours while electrochemically reducing CO2 to multi-carbon hydrocarbons. |
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 |
|
Wos |
000442395200013 |
Publication Date |
2018-07-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1755-4330; 1755-4349 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
25.87 |
Times cited |
700 |
Open Access |
OpenAccess |
Notes |
; This work was supported financially by funding from TOTAL S.A., the Ontario Research Fund: Research Excellence Program, the Natural Sciences and Engineering Research Council of Canada, the CIFAR Bio-Inspired Solar Energy programme, a University of Toronto Connaught grant, the Ministry of Science, Natural Science Foundation of China (21471040, 21271055 and 21501035), the Innovation-Driven Plan in Central South University project (2017CX003), a project from State Key Laboratory of Powder Metallurgy in Central South University, the Thousand Youth Talents Plan of China and Hundred Youth Talents Program of Hunan and the China Scholarship Council programme. This work benefited from the soft X-ray microcharacterization beamline at CLS, sector 20BM at the APS and the Ontario Centre for the Characterisation of Advanced Materials at the University of Toronto. H.Y. acknowledges financial support from the Research Foundation-Flanders (FWO postdoctoral fellowship). C.Z. acknowledges support from the International Academic Exchange Fund for Joint PhD Students from Tianjin University. P.D.L. acknowledges financial support from the Natural Sciences and Engineering Research Council in the form of the Canada Graduate Scholarship-Doctoral award. S.B. and E.B. acknowledge financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). The authors thank B. Zhang, N. Wang, C. T. Dinh, T. Zhuang, J. Li and Y. Zhao for fruitful discussions, as well as Y. Hu and Q. Xiao from CLS, and Z. Finfrock and M. Ward from APS for their help during the course of study. Computations were performed on the SOSCIP Consortium's Blue Gene/Q computing platform. SOSCIP is funded by the Federal Economic Development Agency of Southern Ontario, the Province of Ontario, IBM Canada, Ontario Centres of Excellence, Mitacs and 15 Ontario academic member institutions. ; ecas_sara |
Approved |
Most recent IF: 25.87 |
Call Number |
UA @ lucian @ c:irua:153693UA @ admin @ c:irua:153693 |
Serial |
5091 |
Permanent link to this record |
|
|
|
Author |
Quan, L.N.; Ma, D.; Zhao, Y.; Voznyy, O.; Yuan, H.; Bladt, E.; Pan, J.; de Arquer, F.P.G.; Sabatini, R.; Piontkowski, Z.; Emwas, A.-H.; Todorovic, P.; Quintero-Bermudez, R.; Walters, G.; Fan, J.Z.; Liu, M.; Tan, H.; Saidaminov, M., I; Gao, L.; Li, Y.; Anjum, D.H.; Wei, N.; Tang, J.; McCamant, D.W.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J.; Bakr, O.M.; Lu, Z.-H.; Sargent, E.H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Edge stabilization in reduced-dimensional perovskites |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
170 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Reduced-dimensional perovskites are attractive light-emitting materials due to their efficient luminescence, color purity, tunable bandgap, and structural diversity. A major limitation in perovskite light-emitting diodes is their limited operational stability. Here we demonstrate that rapid photodegradation arises from edge-initiated photooxidation, wherein oxidative attack is powered by photogenerated and electrically-injected carriers that diffuse to the nanoplatelet edges and produce superoxide. We report an edge-stabilization strategy wherein phosphine oxides passivate unsaturated lead sites during perovskite crystallization. With this approach, we synthesize reduced-dimensional perovskites that exhibit 97 +/- 3% photoluminescence quantum yields and stabilities that exceed 300 h upon continuous illumination in an air ambient. We achieve green-emitting devices with a peak external quantum efficiency (EQE) of 14% at 1000 cd m(-2); their maximum luminance is 4.5 x 10(4) cd m(-2) (corresponding to an EQE of 5%); and, at 4000 cd m(-2), they achieve an operational half-lifetime of 3.5 h. |
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 |
|
Language |
|
Wos |
000551458200001 |
Publication Date |
2020-01-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
147 |
Open Access |
OpenAccess |
Notes |
; This publication is based in part on work supported by an award (KUS-11-009-21) from the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, by the Ontario Research Fund (ORF), by the Natural Sciences and Engineering Research Council (NSERC) of Canada, and by the US Department of Navy, Office of Naval Research (Grant Award No. N00014-17-12524). H.Y. acknowledges the Research Foundation-Flanders (FWO Vlaanderen) for a postdoctoral fellowship. E.B. gratefully acknowledges financial support by the Research Foundation-Flanders (FWO Vlaanderen). S.B. acknowledges financial support from European Research Council (ERC Starting Grant #815128-REALNANO). M.B.J.R. and J.H. acknowledge the Research Foundation-Flanders (FWO, Grants G.0962.13, G.0B39.15, AKUL/11/14 and G0H6316N), KU Leuven Research Fund (C14/15/053) and the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ ERC Grant Agreement No. [307523], ERC-Stg LIGHT to M.B.J.R. DFT calculations were performed on the IBM BlueGene Q supercomputer with support from the Southern Ontario Smart Computing Innovation Platform (SOSCIP). M.I.S. acknowledges the Banting Postdoctoral Fellowship program from the Natural Sciences and Engineering Research Council of Canada (NSERC). H.T. acknowledges the Netherlands Organisation for Scientific Research (NWO) for a Rubicon grant (680-50-1511). ; sygma |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:171327 |
Serial |
6496 |
Permanent link to this record |
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|
|
Author |
Ren, Z.; Wu, M.; Chen, X.; Li, W.; Li, M.; Wang, F.; Tian, H.; Chen, J.; Xie, Y.; Mai, J.; Li, X.; Lu, X.; Lu, Y.; Zhang, H.; Van Tendeloo, G.; Zhang, Z.; Han, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Electrostatic force-driven oxide heteroepitaxy for interface control |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
30 |
Issue |
38 |
Pages |
1707017 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Oxide heterostructure interfaces create a platform to induce intriguing electric and magnetic functionalities for possible future devices. A general approach to control growth and interface structure of oxide heterostructures will offer a great opportunity for understanding and manipulating the functionalities. Here, it is reported that an electrostatic force, originating from a polar ferroelectric surface, can be used to drive oxide heteroepitaxy, giving rise to an atomically sharp and coherent interface by using a low-temperature solution method. These heterostructures adopt a fascinating selective growth, and show a saturation thickness and the reconstructed interface with concentrated charges accumulation. The ferroelectric polarization screening, developing from a solid-liquid interface to the heterostructure interface, is decisive for the specific growth. At the interface, a charge transfer and accumulation take place for electrical compensation. The facile approach presented here can be extremely useful for controlling oxide heteroepitaxy and producing intriguing interface functionality via electrostatic engineering. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000444671900002 |
Publication Date |
2018-08-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
4 |
Open Access |
Not_Open_Access |
Notes |
; Z.H.R., M.J.W., and X.C. contributed equally to this work. This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51232006, 51472218, 11474249, 61574123, 11374009, and 11234011), the National 973 Program of China (Grant No. 2015CB654901), National Young 1000 Talents Program of China, the Fundamental Research Funds for the Central Universities (Grant No. 2017FZA4008), and the 111 Project under Grant No. B16042. J.M. and X.L. gratefully thank the beam time and technical supports provided by 23A SWAXS beamline at NSRRC, Hsinchu. ; |
Approved |
Most recent IF: 19.791 |
Call Number |
UA @ lucian @ c:irua:153628 |
Serial |
5098 |
Permanent link to this record |
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|
|
Author |
Huang, S.-Z.; Jin, J.; Cai, Y.; Li, Y.; Tan, H.-Y.; Wang, H.-E.; Van Tendeloo, G.; Su, B.-L. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Engineering single crystalline Mn3O4 nano-octahedra with exposed highly active {011} facets for high performance lithium ion batteries |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
6 |
Issue |
12 |
Pages |
6819-6827 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Well shaped single crystalline Mn3O4 nano-octahedra with exposed highly active {011} facets at different particle sizes have been synthesized and used as anode materials for lithium ion batteries. The electrochemical results show that the smallest sized Mn3O4 nano-octahedra show the best cycling performance with a high initial charge capacity of 907 mA h g−1 and a 50th charge capacity of 500 mA h g−1 at a current density of 50 mA g−1 and the best rate capability with a charge capacity of 350 mA h g−1 when cycled at 500 mA g−1. In particular, the nano-octahedra samples demonstrate a much better electrochemical performance in comparison with irregular shaped Mn3O4 nanoparticles. The best electrochemical properties of the smallest Mn3O4 nano-octahedra are ascribed to the lower charge transfer resistance due to the exposed highly active {011} facets, which can facilitate the conversion reaction of Mn3O4 and Li owing to the alternating Mn and O atom layers, resulting in easy formation and decomposition of the amorphous Li2O and the multi-electron reaction. On the other hand, the best electrochemical properties of the smallest Mn3O4 nano-octahedra can also be attributed to the smallest size resulting in the highest specific surface area, which provides maximum contact with the electrolyte and facilitates the rapid Li-ion diffusion at the electrode/electrolyte interface and fast lithium-ion transportation within the particles. The synergy of the exposed {011} facets and the smallest size (and/or the highest surface area) led to the best performance for the Mn3O4 nano-octahedra. Furthermore, HRTEM observations verify the oxidation of MnO to Mn3O4 during the charging process and confirm that the Mn3O4 octahedral structure can still be partly maintained after 50 dischargecharge cycles. The high Li-ion storage capacity and excellent cycling performance suggest that Mn3O4 nano-octahedra with exposed highly active {011} facets could be excellent anode materials for high-performance lithium-ion batteries. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000337143900072 |
Publication Date |
2014-04-09 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
80 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.367; 2014 IF: 7.394 |
Call Number |
UA @ lucian @ c:irua:117076 |
Serial |
1047 |
Permanent link to this record |
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|
Author |
Angelakeris, M.; Li, Z.A.; Hilgendorff, M.; Simeonidis, K.; Sakellari, D.; Filippousi, M.; Tian, H.; Van Tendeloo, G.; Spasova, M.; Acet, M.; Farle, M. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Enhanced biomedical heat-triggered carriers via nanomagnetism tuning in ferrite-based nanoparticles |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of magnetism and magnetic materials |
Abbreviated Journal |
J Magn Magn Mater |
Volume |
381 |
Issue |
381 |
Pages |
179-187 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Biomedical nanomagnetic carriers are getting a higher impact in therapy and diagnosis schemes while their constraints and prerequisites are more and more successfully confronted. Such particles should possess a well-defined size with minimum agglomeration and they should be synthesized in a facile and reproducible high-yield way together with a controllable response to an applied static or dynamic field tailored for the specific application. Here, we attempt to enhance the heating efficiency in magnetic particle hyperthermia treatment through the proper adjustment of the core-shell morphology in ferrite particles, by controlling exchange and dipolar magnetic interactions at the nanoscale. Thus, core-shell nanoparticles with mutual coupling of magnetically hard (CoFe2O4) and soft (MnFe2O4) components are synthesized with facile synthetic controls resulting in uniform size and shell thickness as evidenced by high resolution transmission electron microscopy imaging, excellent crystallinity and size monodispersity. Such a magnetic coupling enables the fine tuning of magnetic anisotropy and magnetic interactions without sparing the good structural, chemical and colloidal stability. Consequently, the magnetic heating efficiency of CoFe2O4. and MnFe2O4 core-shell nanoparticles is distinctively different horn that of their counterparts, even though all these nanocrystals were synthesized under similar conditions. For better understanding of the AC magnetic hyperthermia response and its correlation with magnetic-origin features we study the effect of the volume ratio of magnetic hard and soft phases in the bimagnetic core-shell nanocrystals. Eventually, such particles may be considered as novel heating carriers that under further biomedical functionalization may become adaptable multifunctional heat-triggered nanoplatforms. (C) 2014 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000349361100027 |
Publication Date |
2014-12-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-8853; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.63 |
Times cited |
20 |
Open Access |
|
Notes |
312483 Esteem2; Esteem2_ta |
Approved |
Most recent IF: 2.63; 2015 IF: 1.970 |
Call Number |
c:irua:125284 c:irua:125284 |
Serial |
1049 |
Permanent link to this record |
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|
Author |
Samal, D.; Tan, H.; Molegraaf, H.; Kuiper, B.; Siemons, W.; Bals, S.; Verbeeck, J.; Van Tendeloo, G.; Takamura, Y.; Arenholz, E.; Jenkins, C.A.; Rijnders, G.; Koster, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Experimental evidence for oxygen sublattice control in polar infinite layer SrCuO2 |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
111 |
Issue |
9 |
Pages |
096102-96105 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A recent theoretical study [ Phys. Rev. B 85 121411(R) (2012)] predicted a thickness limit below which ideal polar cuprates turn nonpolar driven by the associated electrostatic instability. Here we demonstrate this possibility by inducing a structural transformation from the bulk planar to chainlike structure upon reducing the SrCuO2 repeat thickness in SrCuO2/SrTiO3 superlattices with unit-cell precision. Our results, based on structural investigation by x-ray diffraction and high resolution scanning transmission electron microscopy, demonstrate that the oxygen sublattice can essentially be built by design. In addition, the electronic structure of the chainlike structure, as studied by x-ray absorption spectroscopy, shows the signature for preferential hole occupation in the Cu 3d3z2-r2 orbital, which is different from the planar case. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000323610800023 |
Publication Date |
2013-08-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
29 |
Open Access |
|
Notes |
This work was carried out with financial support from AFOSR and EOARD project (Project No. FA8655-10-1-3077) and also supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS and ERC Starting Grant No. 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. This work was partially funded by the European Union Council under the 7th Framework Program (FP7) Grant No. NMP3-LA-2010-246102 IFOX. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure No. 312483-ESTEEM2. Advanced Light Source is supported by the Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. Y. T. acknowledges support from the National Science Foundation (DMR-0747896). W. S. was supported by the US DOE, Basic Energy Sciences, Materials Sciences and Engineering Division. D. S. thanks Z. Zhong from Vienna University of Technology, Austria for scientific discussion. ECASJO_; |
Approved |
Most recent IF: 8.462; 2013 IF: 7.728 |
Call Number |
UA @ lucian @ c:irua:109452UA @ admin @ c:irua:109452 |
Serial |
1140 |
Permanent link to this record |
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|
Author |
Tian, H.; Schryvers, D.; Mohanchandra, K.P.; Carman, G.P.; van Humbeeck, J. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Fabrication and characterization of functionally graded Ni-Ti multilayer thin films |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Functional materials letters |
Abbreviated Journal |
Funct Mater Lett |
Volume |
2 |
Issue |
2 |
Pages |
61-66 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A functionally graded multilayer NiTi thin film was deposited on a SiO2/Si substrate by d.c. sputtering using a ramped heated NiTi alloy target. The stand-alone films were crystallized at 500°C in vacuum better than 10-7 Torr. Transmission electron microscopy micrographs taken along the film cross section show two distinct regions, thin and thick, with weak R and B2 phases, respectively. The film compositions along the thickness were measured and quantified using the standard-less EELSMODEL method. The film deposited during the initial thermal ramp (thin regions) displays an average of 54 at.% Ni while the film deposited at a more elevated target temperature (thick regions) shows about 51 at.% Ni. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000271077000003 |
Publication Date |
2009-07-22 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1793-6047;1793-7213; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.234 |
Times cited |
9 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 1.234; 2009 IF: 2.561 |
Call Number |
UA @ lucian @ c:irua:77655 |
Serial |
1165 |
Permanent link to this record |
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|
Author |
Debroye, E.; Yuan, H.; Bladt, E.; Baekelant, W.; Van der Auweraer, M.; Hofkens, J.; Bals, S.; Roeffaers, M.B.J. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Facile morphology-controlled synthesis of organolead iodide perovskite nanocrystals using binary capping agents |
Type |
A1 Journal article |
Year |
2017 |
Publication |
ChemNanoMat : chemistry of nanomaterials for energy, biology and more |
Abbreviated Journal |
Chemnanomat |
Volume |
3 |
Issue |
3 |
Pages |
223-227 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Controlling the morphology of organolead halide perovskite crystals is crucial to a fundamental understanding of the materials and to tune their properties for device applications. Here, we report a facile solution-based method for morphology-controlled synthesis of rod-like and plate-like organolead halide perovskite nanocrystals using binary capping agents. The morphology control is likely due to an interplay between surface binding kinetics of the two capping agents at different crystal facets. By high-resolution scanning transmission electron microscopy, we show that the obtained nanocrystals are monocrystalline. Moreover, long photoluminescence decay times of the nanocrystals indicate long charge diffusion lengths and low trap/defect densities. Our results pave the way for large-scale solution synthesis of organolead halide perovskite nanocrystals with controlled morphology for future device applications. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000399604300003 |
Publication Date |
2017-01-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2199-692x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.937 |
Times cited |
19 |
Open Access |
OpenAccess |
Notes |
; We acknowledge financial support from the Research Foundation-Flanders (FWO, grant G.0197.11, G.0962.13, G0B39.15, postdoctoral fellowship to E. D. and H. Y.), KU Leuven Research Fund (C14/15/053), the Flemish government through long term structural funding Methusalem (CASAS2, Meth/15/04), the Hercules foundation (HER/11/14), the Belgian Federal Science Policy Office (IAP-PH05), the EC through the Marie Curie ITN project iSwitch (GA-642196) and the ERC project LIGHT (GA307523). S. B. acknowledges financial support from European Research Council (ERC Starting Grant # 335078-COLOURATOMS). E. B. gratefully acknowledges financial support by the Flemish Fund for Scientific Research (FWO Vlaanderen). ; ecas_Sara |
Approved |
Most recent IF: 2.937 |
Call Number |
UA @ lucian @ c:irua:143678UA @ admin @ c:irua:143678 |
Serial |
4656 |
Permanent link to this record |
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|
|
Author |
Theofanidis, S.A.; Galvita, V.V.; Poelman, H.; Dharanipragada, N.V.R.A.; Longo, A.; Meledina, M.; Van Tendeloo, G.; Detavernier, C.; Marin, G.B. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Fe-containing magnesium aluminate support for stability and carbon control during methane reforming |
Type |
A1 Journal article |
Year |
2018 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
Volume |
8 |
Issue |
7 |
Pages |
5983-5995 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report a MgFexAl2-xO4 synthetic spinel, where x varies from 0 to 0.26, as support for Ni-based catalysts, offering stability and carbon control under various conditions of methane reforming. By incorporation of Fe into a magnesium aluminate spine!, a support is created with redox functionality and high thermal stability, as concluded from temporal analysis of products (TAP) experiments and redox cycling, respectively. A diffusion coefficient of 3 x 10(-17) m(2) s(-1) was estimated for lattice oxygen at 993 K from TAP experiments. X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) modeling identified that the incorporation of iron occurs as Fe3+ in the octahedral sites of the spinel lattice, replacing aluminum. Simulation of the X-ray absorption near edge structure (XANES) spectrum of the reduced support showed that 60 +/- 10% of iron was reduced from 3+ to 2+ at 1073 K, while there was no formation of metallic iron. A series of Ni/MgFexAl2-xO4 catalysts, where x varies from 0 to 0.26, was synthesized and reduced, yielding a supported Ni-Fe alloy. The evolution of the catalyst structure during H-2 temperature-programmed reduction (TPR) and CO2 temperature-programmed oxidation (TPO) was examined using time-resolved in situ XRD and XANES. During reforming, iron in both the support and alloy keeps control of carbon accumulation, as confirmed by O-2-TPO on the spent catalysts. By fine tuning the amount of Fe in MgFexAl2-xO4, a supported alloy was obtained with a Ni/Fe molar ratio of similar to 10, which was active for reforming and stable. By comparison of the performance of Ni-based catalysts with Fe either incorporated into or deposited onto the support, the location of Fe within the support proved crucial for the stability and carbon mitigation under reforming conditions. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000438475100034 |
Publication Date |
2018-05-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2155-5435 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.614 |
Times cited |
18 |
Open Access |
OpenAccess |
Notes |
; This work was supported by the FAST industrialization by Catalyst Research and Development (FASTCARD) project, which is a Large Scale Collaborative Project supported by the European Commission in the 7th Framework Programme (GA no 604277), the “Long Term Structural Methusalem Funding by the Flemish Government”, the Interuniversity Attraction Poles Programme, IAP7/5, Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of travel costs and beam time at the DUBBLE beamline of the ESRF. The authors acknowledge the assistance from the DUBBLE (ESRF, XAS campaign 26-01-1048) and ROCK staff (SOLEIL, proposal 201502561). The authors equally acknowledge support from a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d'Avenir” program (reference: ANR-10-EQPX-45) for the ROCK beamline and from Lukas Buelens and Rakesh Batchu (Laboratory for Chemical Technology, Ghent University) for the STEM measurements and TAP experiments, respectively. ; |
Approved |
Most recent IF: 10.614 |
Call Number |
UA @ lucian @ c:irua:153178 |
Serial |
5102 |
Permanent link to this record |
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Author |
Paul, M.; Kufer, D.; Müller, A.; Brück, S.; Goering, E.; Kamp, M.; Verbeeck, J.; Tian, H.; Van Tendeloo, G.; Ingle, N.J.C.; Sing, M.; Claessen, R. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Fe3O4/ZnO : a high-quality magnetic oxide-semiconductor heterostructure by reactive deposition |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
98 |
Issue |
1 |
Pages |
012512,1-012512,3 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We demonstrate the epitaxial growth of Fe<sub>3</sub>O<sub>4</sub> films on ZnO by a simple reactive deposition procedure using molecular oxygen as an oxidizing agent. X-ray photoelectron spectroscopy results evidence that the iron-oxide surface is nearly stoichiometric magnetite. X-ray diffraction results indicate monocrystalline epitaxy and almost complete structural relaxation. Scanning transmission electron micrographs reveal that the microstructure consists of domains which are separated by antiphase boundaries or twin boundaries. The magnetite films show rather slow magnetization behavior in comparison with bulk crystals probably due to reduced magnetization at antiphase boundaries in small applied fields. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000286009800055 |
Publication Date |
2011-01-07 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
27 |
Open Access |
|
Notes |
The authors acknowledge financial support by DFG through Forschergruppe FOR 1162. |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
Call Number |
UA @ lucian @ c:irua:88653 |
Serial |
3532 |
Permanent link to this record |
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Author |
Dehhaghi, S.; Choobchian, S.; Ghobadian, B.; Farhadian, H.; Viira, A.-H.; Stefanie, H.I.; Van Passel, S.; Azadi, H. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Five-year development plans of renewable energy policies in Iran : a content analysis |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Sustainability |
Abbreviated Journal |
Sustainability-Basel |
Volume |
14 |
Issue |
3 |
Pages |
1501 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM) |
Abstract |
Renewable energy (RE) policies can play an effective role in the development of renewable resources. The main goal of this paper was to conduct a content analysis on RE development policies in Iran's five-year National Development Plan (NDP) by investigating upstream national documents. To achieve the goal, 29 upstream documents related to RE were identified and analyzed through a systematic literature review. Then, a qualitative content analysis was applied to analyze the documents. The results showed that Iran's current RE policies need to be reviewed, reformed, and strengthened. For example, lack of sufficient attention to renewable heat and fuel was one of the deficiencies of RE policies in Iran's five-year NDP. The decentralization of policymaking in the unified organization was also one of the weaknesses in the policymaking process of the RE. Iran can develop sustainable and clean RE policies by using sources such as solar, wind, geothermal, hydropower, wave, and tidal power. The paper concludes that, although RE policies have the potential for development in Iran due to environmental, social, and economic advantages, they could face some infrastructural, managerial, socio-cultural, and economic challenges. Accordingly, effective and innovative policymaking is required to meet such challenges. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000754912800001 |
Publication Date |
2022-01-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2071-1050 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.9 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.9 |
Call Number |
UA @ admin @ c:irua:186501 |
Serial |
7358 |
Permanent link to this record |