| Records |
| Author |
Gauquelin, N.; Zhang, H.; Zhu, G.; Wei, J.Y.T.; Botton, G.A. |
| Title |
Atomic-scale identification of novel planar defect phases in heteroepitaxial YBa2Cu3O7-\delta thin films |
Type |
A1 Journal article |
Year  |
2018 |
Publication |
AIP advances |
Abbreviated Journal |
Aip Adv |
| Volume |
8 |
Issue |
5 |
Pages |
055022 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
We have discovered two novel types of planar defects that appear in heteroepitaxial YBa2Cu3O7-delta(YBCO123) thin films, grown by pulsed-laser deposition (PLD) either with or without a La2/3Ca1/3MnO3 (LCMO) overlayer, using the combination of highangle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) mapping for unambiguous identification. These planar lattice defects are based on the intergrowth of either a BaO plane between two CuO chains or multiple Y-O layers between two CuO2 planes, resulting in non-stoichiometric layer sequences that could directly impact the high-Tc superconductivity. (C) 2018 Author(s). |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Institute of Physics |
Place of Publication |
Melville, NY |
Editor |
|
| Language |
|
Wos |
000433954000022 |
Publication Date |
2018-05-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2158-3226 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.568 |
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
; We are thankful to Julia Huang for FIB TEM sample preparation. This work is supported by NSERC (through Discovery Grants to GAB and JYTW) and CIFAR. The electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a National Facility supported by McMaster University, the Canada Foundation for Innovation and NSERC. N.G. acknowledges H. Idrissi for useful discussions. ; |
Approved |
Most recent IF: 1.568 |
| Call Number |
UA @ lucian @ c:irua:152063 |
Serial |
5013 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhang, H.; Gauquelin, N.; McMahon, C.; Hawthorn, D.G.; Botton, G.A.; Wei, J.Y.T. |
| Title |
Synthesis of high-oxidation Y-Ba-Cu-O phases in superoxygenated thin films |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review materials |
Abbreviated Journal |
|
| Volume |
2 |
Issue |
3 |
Pages |
033803 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
It is known that solid-state reaction in high-pressure oxygen can stabilize high-oxidation phases of Y-Ba-Cu-O superconductors in powder form. We extend this superoxygenation concept of synthesis to thin films which, due to their large surface-to-volume ratio, are more reactive thermodynamically. Epitaxial thin films of YBa2Cu3O7-delta grown by pulsed laser deposition are annealed at up to 700 atm O-2 and 900 degrees C, in conjunction with Cu enrichment by solid-state diffusion. The films show the clear formation of Y2Ba4Cu7O15-delta and Y2Ba4Cu8O16 as well as regions of YBa2Cu5O9-delta and YBa2Cu6O10-delta phases, according to scanning transmission electron microscopy, x-ray diffraction, and x-ray absorption spectroscopy. Similarly annealed YBa2Cu3O7-delta powders show no phase conversion. Our results demonstrate a route of synthesis towards discovering more complex phases of cuprates and other superconducting oxides. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
College Park, Md |
Editor |
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| Language |
|
Wos |
000428244900004 |
Publication Date |
2018-03-26 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
2 |
Open Access |
Not_Open_Access |
| Notes |
; This work is supported by NSERC, CFI-OIT, and CIFAR. The electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a National Facility supported by the Canada Foundation for Innovation under the Major Science Initiative program, McMaster University, and NSERC. The XAS work was performed at the Canadian Light Source, which is supported by NSERC, NRC, CIHR, and the University of Saskatchewan. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:150829 |
Serial |
4982 |
| Permanent link to this record |
| |
|
| |
| Author |
Woo, S.Y.; Gauquelin, N.; Nguyen, H.P.T.; Mi, Z.; Botton, G.A. |
| Title |
Interplay of strain and indium incorporation in InGaN/GaN dot-in-a-wire nanostructures by scanning transmission electron microscopy |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
26 |
Issue |
26 |
Pages |
344002 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
The interplay between strain and composition is at the basis of heterostructure design to engineer new properties. The influence of the strain distribution on the incorporation of indium during the formation of multiple InGaN/GaN quantum dots (QDs) in nanowire (NW) heterostructures has been investigated, using the combined techniques of geometric phase analysis of atomic-resolution images and quantitative elemental mapping from core-loss electron energy-loss spectroscopy within scanning transmission electron microscopy. The variation in In-content between successive QDs within individual NWs shows a dependence on the magnitude of compressive strain along the growth direction within the underlying GaN barrier layer, which affects the incorporation of In-atoms to minimize the local effective strain energy. Observations suggest that the interfacial misfit between InGaN/GaN within the embedded QDs is mitigated by strain partitioning into both materials, and results in normal stresses inflicted by the presence of the surrounding GaN shell. These experimental measurements are linked to the local piezoelectric polarization fields for individual QDs, and are discussed in terms of the photoluminescence from an ensemble of NWs. |
| 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 |
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| Language |
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Wos |
000359079500003 |
Publication Date |
2015-08-03 |
| 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 |
19 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.44; 2015 IF: 3.821 |
| Call Number |
UA @ lucian @ c:irua:136278 |
Serial |
4504 |
| Permanent link to this record |
| |
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| |
| Author |
Stambula, S.; Gauquelin, N.; Bugnet, M.; Gorantla, S.; Turner, S.; Sun, S.; Liu, J.; Zhang, G.; Sun, X.; Botton, G.A. |
| Title |
Chemical structure of nitrogen-doped graphene with single platinum atoms and atomic clusters as a platform for the PEMFC electrode |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
118 |
Issue |
8 |
Pages |
3890-3900 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A platform for producing stabilized Pt atoms and clusters through the combination of an N-doped graphene support and atomic layer deposition (ALD) for the Pt catalysts was investigated using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). It was determined, using imaging and spectroscopy techniques, that a wide range of N-dopant types entered the graphene lattice through covalent bonds without largely damaging its structure. Additionally and most notably, Pt atoms and atomic clusters formed in the absence of nanoparticles. This work provides a new strategy for experimentally producing stable atomic and subnanometer cluster catalysts, which can greatly assist the proton exchange membrane fuel cell (PEMFC) development by producing the ultimate surface area to volume ratio catalyst. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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| Language |
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Wos |
000332188100004 |
Publication Date |
2014-02-12 |
| 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 |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
57 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 4.536; 2014 IF: 4.772 |
| Call Number |
UA @ lucian @ c:irua:115571 |
Serial |
352 |
| Permanent link to this record |
| |
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| |
| Author |
Turner, S.; Verbeeck, J.; Ramezanipour, F.; Greedan, J.E.; Van Tendeloo, G.; Botton, G.A. |
| Title |
Atomic resolution coordination mapping in Ca2FeCoO5 brownmillerite by spatially resolved electron energy-loss spectroscopy |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
24 |
Issue |
10 |
Pages |
1904-1909 |
| 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 at high energy resolution in an aberration-corrected electron microscope, we demonstrate the capability of coordination mapping in complex oxides. Brownmillerite compound Ca2FeCoO5, consisting of repetitive octahedral and tetrahedral coordination layers with Fe and Co in a fixed 3+ valency, is selected to demonstrate the principle of atomic resolution coordination mapping. Analysis of the Co-L2,3 and the Fe-L2,3 edges shows small variations in the fine structure that can be specifically attributed to Co/Fe in tetrahedral or in octahedral coordination. Using internal reference spectra, we show that the coordination of the Fe and Co atoms in the compound can be mapped at atomic resolution. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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| Language |
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Wos |
000304237500024 |
Publication Date |
2012-04-25 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
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| ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.466 |
Times cited |
33 |
Open Access |
|
| Notes |
A.M. Abakumov is thanked for fruitful discussions. S.T. gratefully acknowledges the Fund for Scientific Research Flanders (FWO). J.E.G. and GAB. acknowledge the support of the NSERC of Canada through Discovery Grants. The Canadian Centre for Electron Microscopy is a National Facility supported by NSERC and McMaster University and was funded by the Canada Foundation for Innovation and the Ontario Government. Part of this work was supported by funding from the European Research Council under the FP7, ERC Grant N 246791 COUNTATOMS and ERC Starting Grant N 278510 VORTEX. The EMAT microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
| Call Number |
UA @ lucian @ c:irua:98379UA @ admin @ c:irua:98379 |
Serial |
175 |
| Permanent link to this record |
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| |
| Author |
Ramezanipour, F.; Greedan, J.E.; Siewenie, J.; Donaberger, R.L.; Turner, S.; Botton, G.A. |
| Title |
A vacancy-disordered, oxygen-deficient perovskite with long-range magnetic ordering : local and average structures and magnetic properties of Sr2Fe1.5Cr0.5O5 |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| Volume |
51 |
Issue |
4 |
Pages |
2638-2644 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The local and average crystal structures and magnetic properties of the oxygen-deficient perovskite Sr2Fe1.5Cr0.5O5+y were studied using powder X-ray and neutron diffraction, neutron-pair distribution function analysis, and electron energy-loss spectroscopy. This material crystallizes in the cubic Pm3̅m space group, with a = 3.94491(14) Å. The oxygen vacancies are distributed randomly throughout the perovskite-type structure, and the average coordination number of the Fe(Cr) sites is 5. Refinement of the neutron diffraction data indicates y 0.05. This is in discordance with an earlier report on a material with the same nominal composition and cell constant. Electron energy-loss Cr L2,3-edge spectroscopy shows that Cr3+ is present, which is also contrary to previous speculation. Neutron-pair distribution function studies show that a brownmillerite-like model involving ordered vacancies and alternating octahedral and tetrahedral coordination at the metal sites, gives a better description of the local structure out to 5 Å. A remarkable phenomenon determined by neutron diffraction in Sr2Fe1.5Cr0.5O5 is the occurrence of a long-range G-type antiferromagnetic ordering with Tc ≈ 565 K because cubic oxygen-deficient perovskites with B-site disorder usually do not undergo transitions to magnetically ordered states. The observation of long-range antiferromagnetic order and the Tc value are in accordance with previous Mössbauer spectroscopic studies. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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| Language |
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Wos |
000300466300079 |
Publication Date |
2012-01-30 |
| 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 |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
| Call Number |
UA @ lucian @ c:irua:95039 |
Serial |
3828 |
| Permanent link to this record |
| |
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| |
| Author |
Radtke, G.; Botton, G.A.; Verbeeck, J. |
| Title |
Electron inelastic, scattering and anisotropy: the two-dimensional point of view |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
106 |
Issue |
11-12 |
Pages |
1082-1090 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The measurement of the electronic structure of anisotropic materials using energy loss near edge structure (ELNES) spectroscopy is an important field of microanalysis in transmission electron microscopy. We present a novel method to study the angular dependence of electron inelastic scattering in anisotropic materials. This method has been applied to the study of 1s -> pi* and sigma* transitions on the carbon K edge in pyrolitic graphite. An excellent agreement between experimental and theoretical two-dimensional scattering patterns has been found. In particular, the need of a fully relativistic calculation of the inelastic scattering cross-section to explain the experimental results is demonstrated. (c) 2006 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000241592900018 |
Publication Date |
2006-07-04 |
| 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 |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
5 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.843; 2006 IF: 1.706 |
| Call Number |
UA @ lucian @ c:irua:61381UA @ admin @ c:irua:61381 |
Serial |
936 |
| Permanent link to this record |
