| Records |
| Author |
Kinnear, C.; Rodriguez-Lorenzo, L.; Clift, M.J.D.; Goris, B.; Bals, S.; Rothen, B.; Fink, A.S. |
| Title |
Decoupling the shape parameter to assess gold nanorod uptake by mammalian cells |
Type |
A1 Journal article |
Year  |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
8 |
Issue |
8 |
Pages |
16416-16426 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The impact of nanoparticles (NPs) upon biological systems can be fundamentally associated with their physicochemical parameters. A further often-stated tenet is the importance of NP shape on rates of endocytosis. However, given the convoluted parameters concerning the NP-cell interaction, it is experimentally challenging to attribute any findings to shape alone. Herein we demonstrate that shape, below a certain limit, which is specific to nanomedicine, is not important for the endocytosis of spherocylinders by either epithelial or macrophage cells in vitro. Through a systematic approach, we reshaped a single batch of gold nanorods into different aspect ratios resulting in near-spheres and studied their cytotoxicity, (pro-)inflammatory status, and endocytosis/exocytosis. It was found that on a length scale of ~10-90 nm and at aspect ratios less than 5, NP shape has little impact upon their entry into either macrophages or epithelial cells. Conversely, nanorods with an aspect ratio above 5 were preferentially endocytosed by epithelial cells, whereas there was a lack of shape dependent uptake following exposure to macrophages in vitro. These findings have implications both in the understanding of nanoparticle reshaping mechanisms, as well as in the future rational design of nanomaterials for biomedical applications. |
| 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 |
000384531600036 |
Publication Date |
2016-08-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.367 |
Times cited |
23 |
Open Access |
OpenAccess |
| Notes |
The authors would like to thank C. Endes for her help and technical assistance with all cell culture experiments. The work was supported by the Adolphe Merkle Foundation, the Swiss National Science Foundation (PP00P2123373), the Swiss National Science Foundation through the National Centre of Competence in Research Bio-Inspired Materials, the Flemish Fund for Scientific Research (FWO Vlaanderen) through a postdoctoral research grant, and the European Research Council (ERC Starting Grant #335078-COLOURATOMS). The authors also appreciate financial support from the European Union under the Seventh Framework Program (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI).; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 7.367 |
| Call Number |
c:irua:135087 c:irua:135087 |
Serial |
4109 |
| Permanent link to this record |
| |
|
| |
| Author |
Pant, A.; Torun, E.; Chen, B.; Bhat, S.; Fan, X.; Wu, K.; Wright, D.P.; Peeters, F.M.; Soignard, E.; Sahin, H.; Tongay, S. |
| Title |
Strong dichroic emission in the pseudo one dimensional material ZrS3 |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
8 |
Issue |
8 |
Pages |
16259-16265 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Zirconium trisulphide (ZrS3), a member of the layered transition metal trichalcogenides (TMTCs) family, has been studied by angle-resolved photoluminescence spectroscopy (ARPLS). The synthesized ZrS3 layers possess a pseudo one-dimensional nature where each layer consists of ZrS3 chains extending along the b-lattice direction. Our results show that the optical properties of few-layered ZrS3 are highly anisotropic as evidenced by large PL intensity variation with the polarization direction. Light is efficiently absorbed when the E-field is polarized along the chain (b-axis), but the field is greatly attenuated and absorption is reduced when it is polarized vertical to the 1D-like chains as the wavelength of the exciting light is much longer than the width of each 1D chain. The observed PL variation with polarization is similar to that of conventional 1D materials, i.e., nanowires, and nanotubes, except for the fact that here the 1D chains interact with each other giving rise to a unique linear dichroism response that falls between the 2D (planar) and 1D (chain) limit. These results not only mark the very first demonstration of PL polarization anisotropy in 2D systems, but also provide novel insight into how the interaction between adjacent 1D-like chains and the 2D nature of each layer influences the overall optical anisotropy of pseudo-1D materials. Results are anticipated to have an impact on optical technologies such as polarized detectors, near-field imaging, communication systems, and bio-applications relying on the generation and detection of polarized light. |
| 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 |
000384531600018 |
Publication Date |
2016-08-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.367 |
Times cited |
54 |
Open Access |
|
| Notes |
; S. Tongay gratefully acknowledges support from NSF DMR-1552220. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS is supported by a FWO postdoctoral fellowship. ; |
Approved |
Most recent IF: 7.367 |
| Call Number |
UA @ lucian @ c:irua:144656 |
Serial |
4116 |
| Permanent link to this record |
| |
|
| |
| Author |
Turner, S.; Idrissi, H.; Sartori, A.F.; Korneychuck, S.; Lu, Y.-G.; Verbeeck, J.; Schreck, M.; Van Tendeloo, G. |
| Title |
Direct imaging of boron segregation at dislocations in B:diamond heteroepitaxial films |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
8 |
Issue |
8 |
Pages |
2212-2218 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission electron microscopy techniques, revealing the presence of two types of dislocations: edge and mixed-type 45 degrees dislocations. The presence and distribution of B in the sample was studied using annular dark-field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these techniques, a segregation of B at the dislocations in the film is evidenced, which is shown to be intermittent along the dislocation. A single edge-type dislocation was selected to study the distribution of the boron surrounding the dislocation core. By imaging this defect at atomic resolution, the boron is revealed to segregate towards the tensile strain field surrounding the edge-type dislocations. An investigation of the fine structure of the B-K edge at the dislocation core shows that the boron is partially substitutionally incorporated into the diamond lattice and partially present in a lower coordination (sp(2)-like hybridization). |
| Address |
EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium. stuart.turner@uantwerpen.be |
| 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 |
000368860900053 |
Publication Date |
2015-12-21 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.367 |
Times cited |
15 |
Open Access |
|
| Notes |
S. T. acknowledges the fund for scien tific research Flanders (FWO) for a post-doctoral scholarship and under contract number G.0044.13N |
Approved |
Most recent IF: 7.367 |
| Call Number |
c:irua:131597UA @ admin @ c:irua:131597 |
Serial |
4121 |
| Permanent link to this record |
| |
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| |
| Author |
Milovanovic, S.P.; Peeters, F.M. |
| Title |
Characterization of the size and position of electron-hole puddles at a graphene p-n junction |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
27 |
Issue |
27 |
Pages |
105203 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
The effect of an electron-hole puddle on the electrical transport when governed by snake states in a bipolar graphene structure is investigated. Using numerical simulations we show that information on the size and position of the electron-hole puddle can be obtained using the dependence of the conductance on magnetic field and electron density of the gated region. The presence of the scatterer disrupts snake state transport which alters the conduction pattern. We obtain a simple analytical formula that connects the position of the electron-hole puddle with features observed in the conductance. The size of the electron-hole puddle is estimated from the magnetic field and gate potential that maximizes the effect of the puddle on the electrical transport. |
| 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 |
English |
Wos |
000369849200003 |
Publication Date |
2016-02-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
3 |
Open Access |
|
| Notes |
This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. We acknowledge interesting correspondence with Thiti Taychatanapat. |
Approved |
Most recent IF: 3.44 |
| Call Number |
c:irua:131907 |
Serial |
4025 |
| Permanent link to this record |
| |
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| |
| Author |
Spadaro, M.C.; Luches, P.; Bertoni, G.; Grillo, V.; Turner, S.; Van Tendeloo, G.; Valeri, S.; D'Addato, S. |
| Title |
Influence of defect distribution on the reducibility of CeO2-x nanoparticles |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
27 |
Issue |
27 |
Pages |
425705 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties. |
| Address |
Dipartimento FIM, Universita di Modena e Reggio Emilia, via G. Campi 213/a, I-41125 Modena, Italy. CNR-NANO, via G. Campi 213/a, I-41125 Modena, Italy |
| 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 |
000385483900004 |
Publication Date |
2016-09-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
11 |
Open Access |
|
| Notes |
The authors gratefully acknowledge financial support by the Italian MIUR under grant FIRB RBAP115AYN (Oxides at the nanoscale: multifunctionality and applications). The activity is performed within the COST Action CM1104 'Reducible oxide chemistry, structure and functions'. The research leading to these results has received funding also from the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative–I3).; esteem2_ta |
Approved |
Most recent IF: 3.44 |
| Call Number |
EMAT @ emat @ c:irua:135424 |
Serial |
4130 |
| Permanent link to this record |
| |
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| |
| Author |
Cai, H.; Kang, J.; Sahin, H.; Chen, B.; Suslu, A.; Wu, K.; Peeters, F.; Meng, X.; Tongay, S. |
| Title |
Exciton pumping across type-I gallium chalcogenide heterojunctions |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
27 |
Issue |
27 |
Pages |
065203 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Quasi-two-dimensional gallium chalcogenide heterostructures are created by transferring exfoliated few-layer GaSe onto bulk GaTe sheets. Luminescence spectroscopy measurements reveal that the light emission from underlying GaTe layers drastically increases on heterojunction regions where GaSe layers make contact with the GaTe. Density functional theory (DFT) and band offset calculations show that conduction band minimum (CBM) (valance band maximum (VBM)) values of GaSe are higher (lower) in energy compared to GaTe, forming type-I band alignment at the interface. Consequently, GaSe layers provide photo-excited electrons and holes to GaTe sheets through relatively large built-in potential at the interface, increasing overall exciton population and light emission from GaTe. Observed results are not specific to the GaSe/GaTe system but observed on GaS/GaSe heterolayers with type-I band alignment. Observed experimental findings and theoretical studies provide unique insights into interface effects across dissimilar gallium chalcogenides and offer new ways to boost optical performance by simple epitaxial coating. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000368897100008 |
Publication Date |
2016-01-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
15 |
Open Access |
|
| Notes |
; This work was supported by the Arizona State University seeding program, the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. HS is supported by a FWO Pegasus Long Marie Curie Fellowship. JK is supported by a FWO Pegasus-short Marie Curie Fellowship. We acknowledge the use of the John M Cowley Center for High Resolution Electron Microscopy at Arizona State University. The authors thank Anupum Pant for useful discussions. We gratefully acknowledge the use of the facilities at the LeRoy Eyring Center for Solid State Science at Arizona State University. S Tongay acknowledges support from DMR-1552220. ; |
Approved |
Most recent IF: 3.44 |
| Call Number |
UA @ lucian @ c:irua:131570 |
Serial |
4179 |
| Permanent link to this record |
| |
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| |
| Author |
Kiymaz, D.; Yagmurcukardes, M.; Tomak, A.; Sahin, H.; Senger, R.T.; Peeters, F.M.; Zareie, H.M.; Zafer, C. |
| Title |
Controlled growth mechanism of poly (3-hexylthiophene) nanowires |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
27 |
Issue |
27 |
Pages |
455604 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Synthesis of 1D-polymer nanowires by a self-assembly method using marginal solvents is an attractive technique. While the formation mechanism is poorly understood, this method is essential in order to control the growth of nanowires. Here we visualized the time-dependent assembly of poly (3-hexyl-thiophene-2,5-diyl) (P3HT) nanowires by atomic force microscopy and scanning tunneling microscopy. The assembly of P3HT nanowires was carried out at room temperature by mixing cyclohexanone (CHN), as a poor solvent, with polymer solution in 1,2-dichlorobenzene (DCB). Both pi-pi stacking and planarization, obtained at the mix volume ratio of P3HT (in DCB):CHN (10:7), were considered during the investigation. We find that the length of nanowires was determined by the ordering of polymers in the polymer repetition direction. Additionally, our density functional theory calculations revealed that the presence of DCB and CHN molecules that stabilize the structural distortions due to tail group of polymers was essential for the core-wire formation. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000386132600003 |
Publication Date |
2016-10-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
24 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, the High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules Foundation. HS is supported by a FWO Pegasus-Long Marie Curie Fellowship. HS and RTS acknowledge support from TUBITAK through Project No. 114F397. Also, DA is supported by the Scientific Research Project Fund of Ege University (Project Nr: 12GEE011). ; |
Approved |
Most recent IF: 3.44 |
| Call Number |
UA @ lucian @ c:irua:138159 |
Serial |
4350 |
| Permanent link to this record |
| |
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| |
| Author |
Tomak, A.; Bacaksiz, C.; Mendirek, G.; Sahin, H.; Hur, D.; Gorgun, K.; Senger, R.T.; Birer, O.; Peeters, F.M.; Zareie, H.M. |
| Title |
Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
27 |
Issue |
27 |
Pages |
335601 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000383780500012 |
Publication Date |
2016-07-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
2 |
Open Access |
|
| Notes |
; The authors acknowledge financial support from TUBITAK (PROJECT NO: 112T507). This work was also supported by the Flemish Science Foundation (FWO-Vl). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid-Infrastructure). HS is supported by an FWO Pegasus Long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.44 |
| Call Number |
UA @ lucian @ c:irua:137155 |
Serial |
4363 |
| Permanent link to this record |
| |
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| |
| Author |
Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S. |
| Title |
Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
| Volume |
8 |
Issue |
8 |
Pages |
501-508 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature. |
| Address |
Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, Germany |
| 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 |
000374534100019 |
Publication Date |
2016-04-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1755-4330 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
25.87 |
Times cited |
51 |
Open Access |
|
| Notes |
S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3 |
Approved |
Most recent IF: 25.87 |
| Call Number |
c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593 |
Serial |
4068 |
| Permanent link to this record |
| |
|
| |
| Author |
O'Sullivan, M.; Hadermann, J.; Dyer, M.S.; Turner, S.; Alaria, J.; Manning, T.D.; Abakumov, A.M.; Claridge, J.B.; Rosseinsky, M.J. |
| Title |
Interface control by chemical and dimensional matching in an oxide heterostructure |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
| Volume |
8 |
Issue |
8 |
Pages |
347-353 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Interfaces between different materials underpin both new scientific phenomena, such as the emergent behaviour at oxide interfaces, and key technologies, such as that of the transistor. Control of the interfaces between materials with the same crystal structures but different chemical compositions is possible in many materials classes, but less progress has been made for oxide materials with different crystal structures. We show that dynamical self-organization during growth can create a coherent interface between the perovskite and fluorite oxide structures, which are based on different structural motifs, if an appropriate choice of cations is made to enable this restructuring. The integration of calculation with experimental observation reveals that the interface differs from both the bulk components and identifies the chemical bonding requirements to connect distinct oxide structures. |
| 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 |
000372505500013 |
Publication Date |
2016-02-01 |
| 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 |
28 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 25.87 |
| Call Number |
UA @ lucian @ c:irua:133189 |
Serial |
4199 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, C.; Ke, X.; Wang, J.; Liang, R.; Luo, Z.; Tian, Y.; Yi, D.; Zhang, Q.; Wang, J.; Han, X.-F.; Van Tendeloo, G.; Chen, L.-Q.; Nan, C.-W.; Ramesh, R.; Zhang, J. |
| Title |
Ferroelastic switching in a layered-perovskite thin film |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
7 |
Issue |
7 |
Pages |
10636 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A controllable ferroelastic switching in ferroelectric/multiferroic oxides is highly desirable due to the non-volatile strain and possible coupling between lattice and other order parameter in heterostructures. However, a substrate clamping usually inhibits their elastic deformation in thin films without micro/nano-patterned structure so that the integration of the non-volatile strain with thin film devices is challenging. Here, we report that reversible in-plane elastic switching with a non-volatile strain of approximately 0.4% can be achieved in layered-perovskite Bi2WO6 thin films, where the ferroelectric polarization rotates by 90 degrees within four in-plane preferred orientations. Phase-field simulation indicates that the energy barrier of ferroelastic switching in orthorhombic Bi2WO6 film is ten times lower than the one in PbTiO3 films, revealing the origin of the switching with negligible substrate constraint. The reversible control of the in-plane strain in this layered-perovskite thin film demonstrates a new pathway to integrate mechanical deformation with nanoscale electronic and/or magnetoelectronic applications. |
| Address |
Department of Physics, Beijing Normal University, 100875 Beijing, China |
| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
English |
Wos |
000371020600002 |
Publication Date |
2016-02-03 |
| 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 |
40 |
Open Access |
|
| Notes |
The work in Beijing Normal University is supported by the NSFC under contract numbers 51322207, 51332001 and 11274045. J.Z. also acknowledges the support from National Basic Research Program of China, under contract No. 2014CB920902. G.V.T. acknowledges the funding from the European Research Council under the Seventh Framework Program (FP7), ERC Advanced Grant No. 246791-COUNTATOMS. X.K. acknowledges the funding from NSFC (Grant No.11404016) and Beijing University of Technology (2015-RD-QB-19). J.W. acknowledges the funding from NSFC (Grant number 51472140). L.-Q.C. acknowledges the supporting by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award FG02-07ER46417. R.L. acknowledges Tsinghua National Laboratory for Information Science and Technology (TNList) Cross-discipline Foundation. Z.L. acknowledges the support from the NSFC (No.11374010 and No.11434009). Q.Z. and X.-F.H. acknowledge the funding support from NSFC (Grant No. 11434014). R.R. acknowledges support from the National Science Foundation (Nanosystems Engineering Research Center for Translational Applications of Nanoscale Multiferroic Systems) under grant number EEC-1160504. |
Approved |
Most recent IF: 12.124 |
| Call Number |
c:irua:130978 |
Serial |
4007 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhang, B.; Dugas, R.; Rousse, G.; Rozier, P.; Abakumov, A.M.; Tarascon, J.-M. |
| Title |
Insertion compounds and composites made by ball milling for advanced sodium-ion batteries |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
7 |
Issue |
7 |
Pages |
10308 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Sodium-ion batteries have been considered as potential candidates for stationary energy storage because of the low cost and wide availability of Na sources. However, their future commercialization depends critically on control over the solid electrolyte interface formation, as well as the degree of sodiation at the positive electrode. Here we report an easily scalable ball milling approach, which relies on the use of metallic sodium, to prepare a variety of sodium-based alloys, insertion layered oxides and polyanionic compounds having sodium in excess such as the Na4V2(PO4)(2)F-3 phase. The practical benefits of preparing sodium-enriched positive electrodes as reservoirs to compensate for sodium loss during solid electrolyte interphase formation are demonstrated by assembling full C/P'2-Na-1[Fe0.5Mn0.5]O-2 and C/'Na3+xV2(PO4)(2)F-3' sodium-ion cells that show substantial increases (>10%) in energy storage density. Our findings may offer electrode design principles for accelerating the development of the sodium-ion technology. |
| 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 |
000369021400002 |
Publication Date |
2016-01-18 |
| 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 |
104 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 12.124 |
| Call Number |
UA @ lucian @ c:irua:131599 |
Serial |
4197 |
| Permanent link to this record |
| |
|
| |
| Author |
Mefford, J.T.; Rong, X.; Abakumov, A.M.; Hardin, W.G.; Dai, S.; Kolpak, A.M.; Johnston, K.P.; Stevenson, K.J. |
| Title |
Water electrolysis on La1-xSrxCoO3-\delta perovskite electrocatalysts |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
7 |
Issue |
7 |
Pages |
11053 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1 – xSrxCoO3 – delta. We attempt to rationalize the high activities of La1 – xSrxCoO3 – delta through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000372721700001 |
Publication Date |
2016-03-23 |
| 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 |
278 |
Open Access |
|
| Notes |
Financial support for this work was provided by the R.A. Welch Foundation (grants F-1529 and F-1319). X.R. and A.M.K. acknowledge support from the Skoltech-MIT Center for Electrochemical Energy Storage. Computations were performed using computational resources from XSEDE and NERSC. S.D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. We thank D.W. Redman for help with the RHE measurements. |
Approved |
Most recent IF: 12.124 |
| Call Number |
UA @ lucian @ c:irua:133242 |
Serial |
4276 |
| Permanent link to this record |
| |
|
| |
| Author |
Schouteden, K.; Amin-Ahmadi, B.; Li, Z.; Muzychenko, D.; Schryvers, D.; Van Haesendonck, C. |
| Title |
Electronically decoupled stacking fault tetrahedra embedded in Au(111) films |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
7 |
Issue |
7 |
Pages |
14001 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Stacking faults are known as defective structures in crystalline materials that typically lower the structural quality of the material. Here, we show that a particular type of defects, i.e., stacking fault tetrahedra (SFTs), exhibits quantized, particle-in-a-box electronic behaviour, revealing a potential synthetic route to decoupled nanoparticles in metal films. We report on the electronic properties of SFTs that exist in Au(111) films, as evidenced by scanning tunnelling microscopy and confirmed by transmission electron microscopy. We find that the SFTs reveal a remarkable decoupling from their metal surroundings, leading to pronounced energy level quantization effects within the SFTs. The electronic behaviour of the SFTs can be described well by the particle-in-a-box model. Our findings demonstrate that controlled preparation of SFTs may offer an alternative way to achieve well decoupled nanoparticles of high crystalline quality in metal thin films without the need of thin insulating layers. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
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Editor |
|
| Language |
|
Wos |
000390367700001 |
Publication Date |
2016-12-23 |
| 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 |
7 |
Open Access |
|
| Notes |
The research in Leuven has been supported by the Research Foundation – Flanders (FWO, Belgium), and by the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. acknowledges the support from the China Scholarship Council (No. 2011624021) and from Internal Funds KU Leuven. K.S. acknowledges additional support from the FWO. The research in Moscow has been supported by grants of the Russian Foundation for Basic Research (RFBR). |
Approved |
Most recent IF: 12.124 |
| Call Number |
EMAT @ emat @ c:irua:138983 |
Serial |
4336 |
| Permanent link to this record |
| |
|
| |
| Author |
Wu, K.; Torun, E.; Sahin, H.; Chen, B.; Fan, X.; Pant, A.; Wright, D.P.; Aoki, T.; Peeters, F.M.; Soignard, E.; Tongay, S. |
| Title |
Unusual lattice vibration characteristics in whiskers of the pseudo-one-dimensional titanium trisulfide TiS3 |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
7 |
Issue |
|
Pages |
12952 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Transition metal trichalcogenides form a class of layered materials with strong in-plane anisotropy. For example, titanium trisulfide (TiS3) whiskers are made out of weakly interacting TiS3 layers, where each layer is made of weakly interacting quasi-one-dimensional chains extending along the b axis. Here we establish the unusual vibrational properties of TiS3 both experimentally and theoretically. Unlike other two-dimensional systems, the Raman active peaks of TiS3 have only out-of-plane vibrational modes, and interestingly some of these vibrations involve unique rigid-chain vibrations and S-S molecular oscillations. High-pressure Raman studies further reveal that the A(g)(S-S) S-S molecular mode has an unconventional negative pressure dependence, whereas other peaks stiffen as anticipated. Various vibrational modes are doubly degenerate at ambient pressure, but the degeneracy is lifted at high pressures. These results establish the unusual vibrational properties of TiS3 with strong in-plane anisotropy, and may have relevance to understanding of vibrational properties in other anisotropic two-dimensional material systems. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000385444300004 |
Publication Date |
2016-09-22 |
| 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 |
50 |
Open Access |
|
| Notes |
; S.T. acknowledges support from the National Science Foundation (DMR-1552220) and (CMMI-1561839). F.M.P., H.S. and E.T. were supported by the Flemish Science Foundation (FWO-Vl). Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e Infrastructure). H.S. acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP programme. F.P. acknowledges the funding from Flemish Science Foundation (FWO-Vl). K.W. acknowledges helpful discussions with H. Cai, W. Kong and X. Meng. We gratefully acknowledge the use of facilities within the LeRoy Eyring Center for Solid State Science at Arizona State University. ; |
Approved |
Most recent IF: 12.124 |
| Call Number |
UA @ lucian @ c:irua:144662 |
Serial |
4700 |
| Permanent link to this record |
| |
|
| |
| Author |
Liao, Z.; Huijben, M.; Zhong, Z.; Gauquelin, N.; Macke, S.; Green, R.J.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Held, K.; Sawatzky, G.A.; Koster, G.; Rijnders, G. |
| Title |
Controlled lateral anisotropy in correlated manganite heterostructures by interface-engineered oxygen octahedral coupling |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
| Volume |
15 |
Issue |
15 |
Pages |
425-431 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Controlled in-plane rotation of the magnetic easy axis in manganite heterostructures by tailoring the interface oxygen network could allow the development of correlated oxide-based magnetic tunnelling junctions with non-collinear magnetization, with possible practical applications as miniaturized high-switching-speed magnetic random access memory (MRAM) devices. Here, we demonstrate how to manipulate magnetic and electronic anisotropic properties in manganite heterostructures by engineering the oxygen network on the unit-cell level. The strong oxygen octahedral coupling is found to transfer the octahedral rotation, present in the NdGaO3 (NGO) substrate, to the La2/3Sr1/3MnO3 (LSMO) film in the interface region. This causes an unexpected realignment of the magnetic easy axis along the short axis of the LSMO unit cell as well as the presence of a giant anisotropic transport in these ultrathin LSMO films. As a result we possess control of the lateral magnetic and electronic anisotropies by atomic-scale design of the oxygen octahedral rotation. |
| Address |
MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands |
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Wos |
000372591700017 |
Publication Date |
2016-03-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1476-1122 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
39.737 |
Times cited |
273 |
Open Access |
|
| Notes |
We would like to acknowledge Dr. Evert Houwman for stimulated discussion. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010- 246102 IFOX. J.V. and S.V.A. acknowledges funding from FWO project G.0044.13N and G. 0368.15N. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., S.V.A., J.V. and G.V.T. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Z.Z. acknowledges funding from the SFB ViCoM (Austrian Science Fund project ID F4103- N13), and Calculations have been done on the Vienna Scientific Cluster (VSC).; esteem2jra2; esteem2jra3 ECASJO_; |
Approved |
Most recent IF: 39.737 |
| Call Number |
c:irua:133190 c:irua:133190UA @ admin @ c:irua:133190 |
Serial |
4041 |
| Permanent link to this record |
| |
|
| |
| Author |
Geuchies, J.J.; van Overbeek, C.; Evers, W.H.; Goris, B.; de Backer, A.; Gantapara, A.P.; Rabouw, F.T.; Hilhorst, J.; Peters, J.L.; Konovalov, O.; Petukhov, A.V.; Dijkstra, M.; Siebbeles, L.D.A.; van Aert, S.; Bals, S.; Vanmaekelbergh, D. |
| Title |
In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
| Volume |
15 |
Issue |
15 |
Pages |
1248-1254 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Oriented attachment of PbSe nanocubes can result in the formation of two-dimensional (2D) superstructures with long-range nanoscale and atomic order. This questions the applicability of classic models in which the superlattice grows by first forming a nucleus, followed by sequential irreversible attachment of nanocrystals, as one misaligned attachment would disrupt the 2D order beyond repair. Here, we demonstrate the formation mechanism of 2D PbSe superstructures with square geometry by using in situ grazing-incidence X-ray scattering (small angle and wide angle), ex situ electron microscopy, and Monte Carlo simulations. We observed nanocrystal adsorption at the liquid/gas interface, followed by the formation of a hexagonal nanocrystal monolayer. The hexagonal geometry transforms gradually through a pseudo-hexagonal phase into a phase with square order, driven by attractive interactions between the {100} planes perpendicular to the liquid substrate, which maximize facet-to-facet overlap. The nanocrystals then attach atomically via a necking process, resulting in 2D square superlattices. |
| Address |
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3584 CC Utrecht, The Netherlands |
| 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 |
English |
Wos |
000389104400011 |
Publication Date |
2016-09-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1476-1122 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
39.737 |
Times cited |
182 |
Open Access |
OpenAccess |
| Notes |
This research is part of the programme ‘Designing Dirac Carriers in semiconductor honeycomb superlattices (DDC13),’ which is supported by the Foundation for Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO). J.J.G. acknowledges funding from the Debye and ESRF Graduate Programs. The authors gratefully acknowledge funding from the Research Foundation Flanders (G.036915 G.037413 and funding of postdoctoral grants to B.G. and A.d.B). S.B. acknowledges the European Research Council, ERC grant No 335078—Colouratom. The authors gratefully acknowledge I. Swart and M. van Huis for fruitful discussions. We acknowledge funding from NWO-CW TOPPUNT ‘Superficial Superstructures’. The X-ray scattering measurements were performed at the ID10 beamline at ESRF under proposal numbers SC-4125 and SC-3786. The authors thank G. L. Destri and F. Zontone for their support during the experiments.; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 39.737 |
| Call Number |
EMAT @ emat @ c:irua:136165 |
Serial |
4289 |
| Permanent link to this record |
| |
|
| |
| Author |
Mao, J.; Jiang, Y.; Moldovan, D.; Li, G.; Watanabe, K.; Taniguchi, T.; Masir, M.R.; Peeters, F.M.; Andrei, E.Y. |
| Title |
Realization of a tunable artificial atom at a supercritically charged vacancy in graphene |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
| Volume |
12 |
Issue |
12 |
Pages |
545-549 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Graphene’s remarkable electronic properties have fuelled the vision of a graphene-based platform for lighter, faster and smarter electronics and computing applications. One of the challenges is to devise ways to tailor graphene’s electronic properties and to control its charge carriers. Here we show that a single-atom vacancy in graphene can stably host a local charge and that this charge can be gradually built up by applying voltage pulses with the tip of a scanning tunnelling microscope. The response of the conduction electrons in graphene to the local charge is monitored with scanning tunnelling and Landau level spectroscopy, and compared to numerical simulations. As the charge is increased, its interaction with the conduction electrons undergoes a transition into a supercritical regime where itinerant electrons are trapped in a sequence of quasi-bound states which resemble an artificial atom. The quasi-bound electron states are detected by a strong enhancement of the density of states within a disc centred on the vacancy site which is surrounded by halo of hole states. We further show that the quasi-bound states at the vacancy site are gate tunable and that the trapping mechanism can be turned on and off, providing a mechanism to control and guide electrons in graphene. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000377475700011 |
Publication Date |
2016-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1745-2473 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
22.806 |
Times cited |
93 |
Open Access |
|
| Notes |
; Funding was provided by DOE-FG02-99ER45742 (STM/STS), NSF DMR 1207108 (fabrication and characterization). Theoretical work supported by ESF-EUROCORES-EuroGRAPHENE, FWO-VI and Methusalem programme of the Flemish government. We thank V. F. Libisch, M. Pereira and E. Rossi for useful discussions. ; |
Approved |
Most recent IF: 22.806 |
| Call Number |
c:irua:134210 |
Serial |
4011 |
| Permanent link to this record |
| |
|
| |
| Author |
Yuan, R.; Claes, N.; Verheyen, E.; Tuel, A.; Bals, S.; Breynaert, E.; Martens, J.; Kirschhock, C.E.A. |
| Title |
Synthesis of IWW-type germanosilicate zeolite using 5-azonia-spiro[4, 4]nonane as structure directing agent |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
New journal of chemistry |
Abbreviated Journal |
New J Chem |
| Volume |
40 |
Issue |
40 |
Pages |
4319-4324 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
IWW-type zeolite with Si/Ge of 4.9 is obtained using 5-azonia-spiro[4,4]nonane as template in fluoride-free medium under hydrothermal conditions at 175 °C. In an otherwise identical synthesis, using the related 5-azonia-spiro[4,5]decane as structure directing agent, a mixture of IWW and NON zeolite types was formed. In absence of GeO2 from the reactant mixture, pure NON formed. The IWW zeolite was characterized by XRD, SEM, and HRTEM. IWW zeolite displayed a unique morphology and could be calcined at 600 °C without loss of crystallinity. The Si/Ge ratio of the IWW zeolite was increased by postsynthesis modification. Part of the germanium could be eliminated from the as-synthesized IWW zeolite by acid leaching using 6 M HCl solution. Also the calcined material could be degermanated. Here the presence of a silicon source in the acidic leaching solution minimized structural damage. This way the Si/Ge ratio of the IWW zeolite was increased from 4.9 up to 10. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000375586400038 |
Publication Date |
2016-02-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1144-0546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.269 |
Times cited |
8 |
Open Access |
OpenAccess |
| Notes |
The authors acknowledge FWO/NWO and ESRF for providing beam time at the DUBBLE and SNBL beamlines (ESRF, Grenoble) and P. Abdala for her assistance during the use of the beamline. The authors are grateful to L. Van Tendeloo for taking SEM images. I. Cuppens and K. Houthoofd are thanked for the ICP and AAS measurements. R.Y. acknowledges Chinese Scholarship Council for a CSC doctoral fellowship. JAM and CEAK acknowledge the Flemish government for long-term structural funding (Methusalem). N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS).; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 3.269 |
| Call Number |
c:irua:133671 |
Serial |
4027 |
| Permanent link to this record |
| |
|
| |
| Author |
Meledina, M.; Turner, S.; Filippousi, M.; Leus, K.; Lobato, I.; Ramachandran, R.K.; Dendooven, J.; Detavernier, C.; Van Der Voort, P.; Van Tendeloo, G. |
| Title |
Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL-101 |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
33 |
Issue |
33 |
Pages |
382-387 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
MIL-101 giant-pore metal-organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration-corrected annular dark-field scanning transmission electron microscopy under strictly controlled low dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal-organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well-suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark-field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000379970000006 |
Publication Date |
2016-02-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.474 |
Times cited |
11 |
Open Access |
|
| Notes |
S.T. and J.D. gratefully acknowledge the FWO Vlaanderen for a postdoctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. K.L. acknowledges the financial support from the Ghent University BOF postdoctoral Grant 01P06813T and UGent GOA Grant 01G00710. C.D. thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513), and the Hercules Foundation (AUGE/09/014) for financial support. |
Approved |
Most recent IF: 4.474 |
| Call Number |
c:irua:131913 |
Serial |
4028 |
| Permanent link to this record |
| |
|
| |
| Author |
Zanaga, D.; Altantzis, T.; Polavarapu, L.; Liz-Marzán, L.M.; Freitag, B.; Bals, S. |
| Title |
A New Method for Quantitative XEDS Tomography of Complex Heteronanostructures |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
33 |
Issue |
33 |
Pages |
396-403 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Reliable quantification of 3D results obtained by X-ray Energy Dispersive Spectroscopy (XEDS) tomography is currently hampered by the presence of shadowing effects and poor spatial resolution. Here, we present a method that overcomes these problems by synergistically combining quantified XEDS data and High Angle Annular Dark Field – Scanning Transmission Electron Microscopy (HAADF-STEM) tomography. As a proof of principle, the approach is applied to characterize a complex Au/Ag nanorattle obtained through a galvanic replacement reaction. However, the technique we propose here is widely applicable to a broad range of nanostructures. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000379970000008 |
Publication Date |
2016-03-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.474 |
Times cited |
29 |
Open Access |
OpenAccess |
| Notes |
The authors acknowledge financial support from European Research Council (ERC Starting Grant # 335078-COLOURATOMS, ERC Advanced Grant # 291667 HierarSACol and ERC Advanced Grant 267867 – PLASMAQUO), the European Union under the FP7 (Integrated Infrastructure Initiative N. 262348 European Soft Matter Infrastructure, ESMI and N. 312483 ESTEEM2).; esteem2jra4; ECASSara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 4.474 |
| Call Number |
c:irua:132643 c:irua:132643 |
Serial |
4052 |
| Permanent link to this record |
| |
|
| |
| Author |
Varambhia, A.M.; Jones, L.; De Backer, A.; Fauske, V.T.; Van Aert, S.; Ozkaya, D.; Nellist, P.D. |
| Title |
Quantifying a Heterogeneous Ru Catalyst on Carbon Black Using ADF STEM |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
33 |
Issue |
33 |
Pages |
438-444 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Ru catalysts are part of a set of late transition metal nanocatalysts that have garnered much interest for catalytic applications such as ammonia synthesis and fuel cell production. Their performance varies greatly depending on their morphology and size, these catalysts are widely studied using electron microscopy. Using recent developments in Annular Dark Field (ADF) Scanning Transmission Electron Microscopy (STEM) quantification techniques, a rapid atom counting procedure was utilized to document the evolution of a heterogeneous Ru catalyst supported on carbon black. Areas of the catalyst were imaged for approximately 15 minutes using ADF STEM. When the Ru clusters were exposed to the electron beam, the clusters changed phase from amorphous to crystalline. To quantify the thickness of the crystalline clusters, two techniques were applied (simulation and statistical decomposition) and compared. These techniques show that stable face centredcubic crystal structures in the form of rafts, between 2 and 8 atoms thick, were formed after the initial wetting of the carbon support. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000379970000012 |
Publication Date |
2016-06-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.474 |
Times cited |
4 |
Open Access |
|
| Notes |
The authors would like to thank the EPSRC and Johnson Matthey for funding this work as part of a CASE-Award studentship. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). We would like to thank Brian Theobald and Jonathan Sharman from JMTC for provision of the samples The authors gratefully acknowledge the Research Foundation Flanders (FWO, Belgium) for funding and for a postdoctoral grant to ADB. The microscope used was funded by the INFRASTRUKTUR Grant 197405 (NORTEM) program of the Research Council of Norway.; esteem2_jra2 |
Approved |
Most recent IF: 4.474 |
| Call Number |
c:irua:134036 c:irua:134036 |
Serial |
4086 |
| Permanent link to this record |
| |
|
| |
| Author |
Chinchilla, L.E.; Olmos, C.; Kurttepeli, M.; Bals, S.; Van Tendeloo, G.; Villa, A.; Prati, L.; Blanco, G.; Calvino, J.J.; Chen, X.; Hungría, A.B. |
| Title |
Combined macroscopic, nanoscopic, and atomic-scale characterization of gold-ruthenium bimetallic catalysts for octanol oxidation |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
33 |
Issue |
33 |
Pages |
419-437 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A series of gold-ruthenium bimetallic catalysts of increasing Au:Ru molar ratios supported on a Ce0.62Zr0.38O2 mixed oxide are prepared and their structural and chemical features characterized by a combination of macroscopic and atomic-scale techniques based on scanning transmission electron microscopy. The influence of the temperature of the final reduction treatment used as activation step (350-700 degrees C range) is also investigated. The preparation method used allows catalysts to be successfully prepared where a major fraction of the metal nanoparticles is in the size range below 5 nm. The structural complexities characteristic of this type of catalysts are evidenced, as well as the capabilities and limitations of both the macroscopic and microscopic techniques in the characterization of the system of metal nanoparticles. A positive influence of the addition of Ru on both the resistance against sintering and the catalytic performance of the starting supported Au catalyst is evidenced. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000379970000011 |
Publication Date |
2016-05-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.474 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
; This work was supported by the Ministry of Science and Innovation of Spain/ FEDER Program of the EU (Project Nos.: MAT 2013-40823-R and CSD2009-00013), ESTEEM2 (FP7-INFRASTUCTURE-2012-1-312493), Junta de Andalucia (FQM334 and FQM110 and Project: FQM3994). S.B. acknowledges the European Research Council, ERC grant No. 335078 – Colouratom. M.K. is grateful to the Fund for Scientific Research Flanders. X.C. thanks the Ramon y Cajal Program. ; ecas_sara |
Approved |
Most recent IF: 4.474 |
| Call Number |
UA @ lucian @ c:irua:134958 |
Serial |
4150 |
| Permanent link to this record |
| |
|
| |
| Author |
Horzum, S.; Torun, E.; Serin, T.; Peeters, F.M. |
| Title |
Structural, electronic and optical properties of Cu-doped ZnO : experimental and theoretical investigation |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
| Volume |
96 |
Issue |
96 |
Pages |
1743-1756 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Experiments are supplemented with ab initio density functional theory (DFT) calculations in order to investigate how the structural, electronic and optical properties of zinc oxide (ZnO) thin films are modified upon Cu doping. Changes in characteristic properties of doped thin films, that are deposited on a glass substrate by sol-gel dip coating technique, are monitored using X-ray diffraction (XRD) and UV measurements. Our ab initio calculations show that the electronic structure of ZnO can be well described by DFT+U/G(0)W(0) method and we find that Cu atom substitutional doping in ZnO is the most favourable case. Our XRD measurements reveal that the crystallite size of the films decrease with increasing Cu doping. Moreover, we determine the optical constants such as refractive index, extinction coefficient, optical dielectric function and optical energy band gap values of the films by means of UV-Vis transmittance spectra. The optical band gap of ZnO the thin film linearly decreases from 3.25 to 3.20 eV at 5% doping. In addition, our calculations reveal that the electronic defect states that stem from Cu atoms are not optically active and the optical band gap is determined by the ZnO band edges. Experimentally observed structural and optical results are in good agreement with our theoretical results. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000376076500002 |
Publication Date |
2016-05-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1478-6435 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.505 |
Times cited |
29 |
Open Access |
|
| Notes |
; Theoretical part of this work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. Experimental part of this work was supported by Ankara University BAP under Project Number [14B0443001]. ; |
Approved |
Most recent IF: 1.505 |
| Call Number |
UA @ lucian @ c:irua:134161 |
Serial |
4254 |
| Permanent link to this record |
| |
|
| |
| Author |
Ekimov, E.A.; Kudryavtsev, O.S.; Turner, S.; Korneychuk, S.; Sirotinkin, V.P.; Dolenko, T.A.; Vervald, A.M.; Vlasov, I.I. |
| Title |
The effect of molecular structure of organic compound on the direct high-pressure synthesis of boron-doped nanodiamond: Effect of organic compound on synthesis of boron-doped nanodiamond |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
| Volume |
213 |
Issue |
213 |
Pages |
2582-2589 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Evolution of crystalline phases with temperature has been studied in materials produced by high-pressure high-temperature treatment of 9-borabicyclo[3.3.1]nonane dimer (9BBN), triphenylborane and trimesitylborane. The boron-doped diamond nanoparticles with a size below 10 nm were obtained at 8–9 GPa and temperatures 970–1250 °C from 9BBN only. Bridged structure and the presence of boron atom in the carbon cycle of 9BBN were revealed to be a key point for the direct synthesis of doped diamond nanocrystals. The diffusional transformation of the disordered carbon phase is suggested to be the main mechanism of the nanodiamond formation from 9BBN in the temperature range of 970–1400 °C. Aqueous suspensions of primary boron-doped diamond nanocrystals were prepared upon removal of non-diamond phases that opens wide opportunities for application of this new nanomaterial in electronics and biotechnologies. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000388321500006 |
Publication Date |
2016-07-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6300 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.775 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.775 |
| Call Number |
EMAT @ emat @ c:irua:135175 |
Serial |
4120 |
| Permanent link to this record |
| |
|
| |
| Author |
Sankaran, K.J.; Hoang, D.Q.; Srinivasu, K.; Korneychuk, S.; Turner, S.; Drijkoningen, S.; Pobedinskas, P.; Verbeeck, J.; Leou, K.C.; Lin, I.N.; Haenen, K. |
| Title |
|
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
| Volume |
213 |
Issue |
10 |
Pages |
2654-2661 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Utilization of Au and nanocrystalline diamond ( NCD) as interlayers noticeably modifies the microstructure and field electron emission ( FEE) properties of hexagonal boron nitride nanowalls ( hBNNWs) grown on Si substrates. The FEE properties of hBNNWs on Au could be turned on at a low turn-on field of 14.3V mu m(-1), attaining FEE current density of 2.58mAcm(-2) and life-time stability of 105 min. Transmission electron microscopy reveals that the Au-interlayer nucleates the hBN directly, preventing the formation of amorphous boron nitride ( aBN) in the interface, resulting in enhanced FEE properties. But Au forms as droplets on the Si substrate forming again aBN at the interface. Conversely, hBNNWs on NCD shows superior in life-time stability of 287 min although it possesses inferior FEE properties in terms of larger turn-on field and lower FEE current density as compared to that of hBNNWs-Au. The uniform and continuous NCD film on Si also circumvents the formation of aBN phases and allows hBN to grow directly on NCD. Incorporation of carbon in hBNNWs from the NCD-interlayer improves the conductivity of hBNNWs, which assists in transporting the electrons efficiently from NCD to hBNNWs that results in better field emission of electrons with high life-time stability. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000388321500017 |
Publication Date |
2016-09-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6300 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.775 |
Times cited |
5 |
Open Access |
|
| Notes |
The authors like to thank the financial support of the Research Foundation Flanders (FWO) via Research Projects G.0456.12 and G.0044.13N, the Methusalem “NANO” network. K. J. Sankaran, P. Pobedinskas, and S. Turner are FWO Postdoctoral Fellows of the Research Foundations Flanders (FWO). |
Approved |
Most recent IF: 1.775 |
| Call Number |
UA @ lucian @ c:irua:144644UA @ admin @ c:irua:144644 |
Serial |
4655 |
| Permanent link to this record |
| |
|
| |
| Author |
Michel, K.H.; Neek-Amal, M.; Peeters, F.M. |
| Title |
Static flexural modes and piezoelectricity in 2D and layered crystals |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
| Volume |
253 |
Issue |
253 |
Pages |
2311-2315 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Piezo- and flexoelectricity are manifestations of electromechanical coupling in solids with potential applications in nanoscale materials. Naumov etal. [Phys. Rev. Lett. 102, 217601 (2009)] have shown by first principles calculations that a monolayer BN sheet becomes macroscopically polarized in-plane when in a corrugated state. Here, we investigate the interplay of layer corrugation and in-plane polarization by atomistic lattice dynamics. We treat the coupling between static flexural modes and in-plane atomic ion displacements as an anharmonic effect, similar to the membrane effect that is at the origin of negative thermal expansion in layered crystals. We have derived analytical expressions for the corrugation-induced static in-plane strains and the optical displacements with the resulting polarization response functions. Beyond h-BN, the theory applies to transition metal dichalcogenides and dioxides. Numerical calculations show that the effects are considerably stronger for 2D h-BN than for 2H-MoS2. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
000390339000002 |
Publication Date |
2016-10-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0370-1972 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.674 |
Times cited |
5 |
Open Access |
|
| Notes |
; The authors acknowledge useful discussions with L. Wirtz, A. Molina-Sanchez, and C. Sevik. This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 1.674 |
| Call Number |
UA @ lucian @ c:irua:140309 |
Serial |
4462 |
| Permanent link to this record |
| |
|
| |
| Author |
Berdiyorov, G.R.; Bahlouli, H.; Peeters, F.M. |
| Title |
Effect of substitutional impurities on the electronic transport properties of graphene |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
| Volume |
84 |
Issue |
84 |
Pages |
22-26 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Density-functional theory in combination with the nonequilibrium Green's function formalism is used to study the effect of substitutional doping on the electronic transport properties of hydrogen passivated zig-zag graphene nanoribbon devices. B, N and Si atoms are used to substitute carbon atoms located at the center or at the edge of the sample. We found that Si -doping results in better electronic transport as compared to the other substitutions. The transmission spectrum also depends on the location of the substitutional dopants: for single atom doping the largest transmission is obtained for edge substitutions, whereas substitutions in the middle of the sample give larger transmission for double carbon substitutions. The obtained results are explained in terms of electron localization in the system due to the presence of impurities. (C) 2016 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000382489600004 |
Publication Date |
2016-05-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1386-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.221 |
Times cited |
17 |
Open Access |
|
| Notes |
; H.B. and F.M.P. acknowledge the support from King Fahd University of Petroleum and Minerals, Saudi Arabia, under research group project RG1329-1 and RG1329-2. G.R.B. acknowledges fruitful discussions with Dr. M.E. Madjet from Qatar Environment and Energy Research Institute. ; |
Approved |
Most recent IF: 2.221 |
| Call Number |
UA @ lucian @ c:irua:135699 |
Serial |
4301 |
| Permanent link to this record |
| |
|
| |
| Author |
Filez, M.; Redekop, E.A.; Galvita, V.V.; Poelman, H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Bell, A.T.; Marin, G.B. |
| 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 |
| Volume |
18 |
Issue |
18 |
Pages |
3234-3243 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| 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. |
| Address |
Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 914, B-9052 Ghent, Belgium. hilde.poelman@ugent.be |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Wos |
000369506000106 |
Publication Date |
2016-01-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1463-9076 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.123 |
Times cited |
10 |
Open Access |
|
| 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 |
| Call Number |
c:irua:132315 |
Serial |
4000 |
| Permanent link to this record |
| |
|
| |
| Author |
Bercx, M.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. |
| 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 |
| Volume |
18 |
Issue |
18 |
Pages |
20542-20549 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| 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. |
| Address |
EMAT & CMT groups, Department of Physics, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, 2020 Antwerp, Belgium. marnik.bercx@uantwerpen.be |
| 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 |
| 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 |
| 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 |
| Call Number |
c:irua:135091 |
Serial |
4112 |
| Permanent link to this record |
