Records |
Author |
De Dobbelaere, C.; Lourdes Calzada, M.; Bretos, I.; Jimenez, R.; Ricote, J.; Hadermann, J.; Hardy, A.; Van Bael, M.K. |
Title |
Gaining new insight into low-temperature aqueous photochemical solution deposited ferroelectric PbTiO3 films |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Materials chemistry and physics |
Abbreviated Journal |
Mater Chem Phys |
Volume |
174 |
Issue |
|
Pages |
28-40 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The nature of the low-temperature photochemical assisted formation process of ferroelectric lead titanate (PbTiO3) films is studied in the present work. Films are obtained by the deposition of an aqueous solution containing citric acid based (citrato) metal ion complexes with intrinsic UV activity. This UV activity is crucial for the aqueous photochemical solution deposition (aqueous PCSD) route being used. UV irradiation enhances the early decomposition of organics and results in improved electrical properties for the crystalline oxide film, even if the film is crystallized at low temperature. GATR-FTIR shows that UV irradiation promotes the decomposition of organic precursor components, resulting in homogeneous films if applied in the right temperature window during film processing. The organic content, morphology and crystallinity of the irradiated films, achieved at different processing atmospheres and temperatures, is studied and eventually correlated to the functional behavior of the obtained films. This is an important issue, as crystalline films obtained at low temperatures often lack ferroelectric responses. In this work, the film prepared in pure oxygen at the very low temperature of 400 degrees C and after an optimized UV treatment presents a significant remanent polarization value of P-r = 8.8 mu C cm(-2). This value is attributed to the better crystallinity, the larger grain size and the reduced porosity obtained thanks to the early film crystallization effectively achieved through the UV treatment in oxygen. (C) 2016 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 |
Lausanne |
Editor |
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Language |
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Wos |
000373865700005 |
Publication Date |
2016-03-16 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0254-0584 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.084 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.084 |
Call Number |
UA @ lucian @ c:irua:144729 |
Serial |
4659 |
Permanent link to this record |
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Author |
Zhang, F.; Chevalier, J.; Olagnon, C.; Batuk, M.; Hadermann, J.; Van Meerbeek, B.; Vleugels, J. |
Title |
Grain-boundary engineering for aging and slow-crack-growth resistant zirconia |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of dental research |
Abbreviated Journal |
J Dent Res |
Volume |
96 |
Issue |
7 |
Pages |
774-779 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Ceramic materials are prone to slow crack growth, resulting in strength degradation over time. Although yttria-stabilized zirconia (Y-TZP) ceramics have higher crack resistance than other dental ceramics, their aging susceptibility threatens their long-term performance in aqueous environments such as the oral cavity. Unfortunately, increasing the aging resistance of Y-TZP ceramics normally reduces their crack resistance. Our recently conducted systematic study of doping 3Y-TZP with various trivalent cations revealed that lanthanum oxide (La2O3) and aluminum oxide (Al2O3) have the most potent effect to retard the aging kinetics of 3Y-TZP. In this study, the crack-propagation behavior of La2O3 and Al2O3 co-doped 3Y-TZP ceramics was investigated by double-torsion methods. The grain boundaries were examined using scanning transmission electron microscopy and energy-dispersive spectroscopy (STEM-EDS). Correlating these analytic data with hydrothermal aging studies using different doping systems, a strategy to strongly bind the segregated dopant cations with the oxygen vacancies at the zirconia-grain boundary was found to improve effectively the aging resistance of Y-TZP ceramics without affecting the resistance to crack propagation. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
St. Louis, Mo. |
Editor |
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Language |
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Wos |
000403934500010 |
Publication Date |
2017-03-10 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-0345 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.755 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
; This research was supported by the Research Fund of KU Leuven under project 0T/ 10/052 and the Research Foundation-Flanders (FWO-Vlaanderen) under grant G.0431.10N. We thank J.W. Seo for TEM and sample preparations. F. Zhang thanks the Research Fund of KU Leuven for her postdoctoral fellowship (PDM/15/153) and the JECS-Trust for the travel grant (No. 201599) to perform double-torsion testing in the MATEIS lab of INSA, Lyon, France. Jerome Chevalier would like to dedicate this paper to Maria Cattani Lorente, who recently passed away under tragic conditions. She was deeply involved in the study of dental zirconia and we will miss her. The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article. ; |
Approved |
Most recent IF: 4.755 |
Call Number |
UA @ lucian @ c:irua:144161 |
Serial |
4660 |
Permanent link to this record |
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Author |
Chin, C.-M.; Sena, R.P.; Hunter, E.C.; Hadermann, J.; Battle, P.D. |
Title |
Interplay of structural chemistry and magnetism in perovskites : a study of CaLn2Ni2WO9: Ln=La, Pr, Nd |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
251 |
Issue |
|
Pages |
224-232 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Polycrystalline samples of CaLn(2)Ni(2)WO(9) (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a similar to 5.50, b similar to 5.56, c similar to 7.78 angstrom beta similar to 90.1 degrees in space group P2(1)/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O-9 perovskites. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000402581200030 |
Publication Date |
2017-04-22 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
; We thank EPSRC for funding through grant EP/M0189541. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful to Ivan da Silva who provided experimental assistance at ISIS and to Maria Batuk for help with the STEM-EDX analysis. ; |
Approved |
Most recent IF: 2.299 |
Call Number |
UA @ lucian @ c:irua:144179 |
Serial |
4664 |
Permanent link to this record |
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Author |
Batuk, D.; Batuk, M.; Morozov, V.A.; Meert, K.W.; Smet, P.F.; Poelman, D.; Abakumov, A.M.; Hadermann, J. |
Title |
Effect of cation vacancies on the crystal structure and luminescent properties of Ca(0.85-1.5x)Gd(x)Eu(0.1)_(0.05+0.5x)WO(4) (0<x<0.567) scheelite-based red phosphors |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of alloys and compounds |
Abbreviated Journal |
J Alloy Compd |
Volume |
706 |
Issue |
706 |
Pages |
358-369 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The Ca0.85-1.5xGdxEu0.1_0.05-0.5xWO4 (0 < x < 0.567) series of cation-deficient scheelites is investigated to unveil the influence of the cation vacancies on the crystal structure and luminescent properties. The concentration of the vacancies is varied by the heterovalent substitution of Gd3+ for Ca2+, keeping the concentration of the Eu3+ luminescent centers constant in all compounds of the series. The crystal structure of the materials is studied using a combination of transmission electron microscopy and synchrotron X-ray powder diffraction. At low vacancy concentration (x = 0.1, 0.2), cations and cation vacancies are randomly distributed in the structure, and the materials preserve the I41/a symmetry of the parent scheelite structure [x = 0.1: a = 5.25151(1) Å, c = 11.39479(2) Å; x = 0.2: a = 5.25042(1) Å, c = 11.41335(2) Å]. At higher concentration, the cation-vacancy ordering gives rise to incommensurately modulated structures. The x = 0.3 structure has a (3 + 2)D tetragonal symmetry [superspace group I41/a(a,b,0)00(-b,a,0)00, a = 5.24700(1) Å, c = 11.45514(3) Å, q1 = 0.51637(14)a* + 0.80761(13)b*, q2 = -0.80761a* + 0.51637b*]. At x = 0.4, the scheelite basic cell undergoes a monoclinic distortion with the formation of the (3 + 1)D structure [superspace group I2/b(a,b,0)00, a = 5.23757(1) Å, b = 5.25035(1) Å, c = 11.45750(2) Å, g = 90.5120(2) o, q = 0.54206(8)a* + 0.79330(8)b*]. In both structures, the antiphase Ca and (Gd,Eu) occupancy modulations indicate that the ordering between the A cations and vacancies also induces partial Ca/(Gd,Eu) cation ordering. Further increase of the Gd3þ content up to x = 0.567 leads to the formation of a monoclinic phase (space group C2/c) with the Eu2/3WO4-type structure. Despite the difference in the cation-vacancy ordering patterns, all materials in the series demonstrate very similar quantum efficiency and luminescence decay lifetimes. However, the difference in the local coordination environment of the A cation species noticeably affects the line width and the multiplet splitting of the 4f6-4f6 transitions. |
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 |
000397997300045 |
Publication Date |
2017-02-16 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0925-8388 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.133 |
Times cited |
2 |
Open Access |
OpenAccess |
Notes |
This research was supported by FWO (Flanders Research Foundation, project G039211N). V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741).We are grateful to the ESRF for granting the beamtime at the ID22 beamline and to Andy Fitch for the support during the experiment. |
Approved |
Most recent IF: 3.133 |
Call Number |
EMAT @ emat @ c:irua:142367 |
Serial |
4581 |
Permanent link to this record |
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Author |
Rumyantseva, M.N.; Vladimirova, S.A.; Vorobyeva, N.A.; Giebelhaus, I.; Mathur, S.; Chizhov, A.S.; Khmelevsky, N.O.; Aksenenko, A.Y.; Kozlovsky, V.F.; Karakulina, O.M.; Hadermann, J.; Abakumov, A.M.; Gaskov, A.M. |
Title |
p -CoO x / n -SnO 2 nanostructures: New highly selective materials for H 2 S detection |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
Volume |
|
Issue |
|
Pages |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanostructures p-CoOx/n-SnO2 based on tin oxide nanowires have been prepared by two step CVD technique and characterized in detail by XRD, XRF, XPS, HAADF-STEM imaging and EDX-STEM mapping. Depending on the temperature of decomposition of cobalt complex during the second step of CVD synthesis of nanostructures cobalt oxide forms a coating and/or isolated nanoparticles on SnO2 nanowire surface. It was found that cobalt presents in +2 and +3 oxidation states. The measurements of gas sensor properties have been carried out during exposure to CO (14 ppm), NH3 (21 ppm), and H2S (2 ppm) in dry air. The opposite trends were observed in the effect of cobalt oxide on the SnO2 gas sensitivity when detecting CO or NH3 in comparison to H2S. The decrease of sensor signal toward CO and NH3 was attributed to high catalytic activity of Co3O4 in oxidation of these gases. Contrary, the significant increase of sensor signal in the presence of H2S was attributed to the formation of metallic cobalt sulfide and removal of the barrier between p-CoOx and n-SnO2. This effect provides an excellent selectivity of p-CoOx/n-SnO2 nanostructures in H2S detection. |
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 |
000414151800068 |
Publication Date |
2017-08-17 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.401 |
Times cited |
13 |
Open Access |
Not_Open_Access: Available from 10.10.2019
|
Notes |
ERA-Net.Plus, 096 FONSENS ; |
Approved |
Most recent IF: 5.401 |
Call Number |
EMAT @ emat @c:irua:145926 |
Serial |
4710 |
Permanent link to this record |
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|
Author |
Singh, V.; Mehta, B.R.; Sengar, S.K.; Karakulina, O.M.; Hadermann, J.; Kaushal, A. |
Title |
Achieving independent control of core diameter and carbon shell thickness in Pd-C core–shell nanoparticles by gas phase synthesis |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
Volume |
28 |
Issue |
29 |
Pages |
295603 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Pd-C core–shell nanoparticles with independently controllable core size and shell thickness are grown by gas phase synthesis. First, the core size is selected by electrical mobility values of charged particles, and second, the shell thickness is controlled by the concentration of carbon precursor gas. The carbon shell grows by adsorption of carbon precursor gas molecules on the surface of nanoparticles, followed by sintering. The presence of a carbon shell on Pd nanoparticles is potentially important in hydrogen-related applications operating at high temperatures or in catalytic reactions in acidic/aqueous environments. |
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 |
000404633200002 |
Publication Date |
2017-06-28 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
1 |
Open Access |
Not_Open_Access |
Notes |
VS is thankful to the All India Council for Technical Education, India, for providing assistantship under its Quality Improvement Programme. BRM gratefully acknowledges the support of the Nanomission Programme of the Department of Science and Technology (DST), India and Schlumberger Chair Professorship. BRM would also like to acknowledge the support from the project funded by BRNS, DAE, India. |
Approved |
Most recent IF: 3.44 |
Call Number |
EMAT @ emat @c:irua:144831 |
Serial |
4712 |
Permanent link to this record |
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Author |
Vladimirova, S.A.; Rumyantseva, M.N.; Filatova, D.G.; Chizhov, A.S.; Khmelevsky, N.O.; Konstantinova, E.A.; Kozlovsky, V.F.; Marchevsky, A.V.; Karakulina, O.M.; Hadermann, J.; Gaskov, A.M. |
Title |
Cobalt location in p-CoOxIn-SnO2 nanocomposites : correlation with gas sensor performances |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of alloys and compounds |
Abbreviated Journal |
J Alloy Compd |
Volume |
721 |
Issue |
|
Pages |
249-260 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p – n junction. (C) 2017 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 |
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Language |
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Wos |
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Publication Date |
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Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
0925-8388 |
ISBN |
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Additional Links |
UA library record; ; WoS full record; WoS citing articles |
Impact Factor |
3.133 |
Times cited |
|
Open Access |
Not_Open_Access: Available from 10.10.2019
|
Notes |
; This work was supported by ERA-Net.Plus grant N 096 FON-SENS. EPR experiments were performed using the facilities of the Collective Use Center at the Moscow State University. ; |
Approved |
Most recent IF: 3.133 |
Call Number |
UA @ lucian @ c:irua:145142 |
Serial |
4714 |
Permanent link to this record |
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Author |
Tang, Y.; Sena, R.P.; Aydeev, M.; Battle, P.D.; Cadogan, J.M.; Hadermann, J.; Hunter, E.C. |
Title |
Magnetic properties of the 6H perovskite Ba3Fe2TeO9 |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
253 |
Issue |
|
Pages |
347-354 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A polycrystalline sample of Ba3Fe2TeO9 having the 6H perovskite structure has been prepared in a solid-state reaction and studied by a combination of electron microscopy, Mossbauer spectroscopy, magnetometry, X-ray diffraction and neutron diffraction. Partial ordering of Fe3+ and Te6+ cations occurs over the six-coordinate sites; the corner-sharing octahedra are predominantly occupied by the former and the face-sharing octahedra by a 1:1 mixture of the two. On cooling through the temperature range 18 < T/K < 295 an increasing number of spins join an antiferromagnetic backbone running through the structure while the remainder show complex relaxation effects. At 3 K an antiferromagnetic phase and a spin glass coexist. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000406572600047 |
Publication Date |
2017-06-22 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
6 |
Open Access |
OpenAccess |
Notes |
; We thank EPSRC for financial support through grant EP/M018954/1. ; |
Approved |
Most recent IF: 2.299 |
Call Number |
UA @ lucian @ c:irua:145692 |
Serial |
4743 |
Permanent link to this record |
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Author |
Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J. |
Title |
Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
29 |
Issue |
20 |
Pages |
8811-8823 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations. |
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 |
000413884900028 |
Publication Date |
2017-10-24 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
7 |
Open Access |
Not_Open_Access |
Notes |
This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. |
Approved |
Most recent IF: 9.466 |
Call Number |
EMAT @ emat @c:irua:147241 |
Serial |
4768 |
Permanent link to this record |
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Author |
Vishwakarma, M.; Karakulina, O.M.; Abakumov, A.M.; Hadermann, J.; Mehta, B.R. |
Title |
Nanoscale Characterization of Growth of Secondary Phases in Off-Stoichiometric CZTS Thin Films |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of nanoscience and nanotechnology |
Abbreviated Journal |
J Nanosci Nanotechno |
Volume |
18 |
Issue |
3 |
Pages |
1688-1695 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The presence of secondary phases is one of the main issues that hinder the growth of pure kesterite Cu2ZnSnS4 (CZTS) based thin films with suitable electronic and junction properties for efficient solar cell devices. In this work, CZTS thin films with varied Zn and Sn content have been prepared by RF-power controlled co-sputtering deposition using Cu, ZnS and SnS targets and a subsequent sulphurization step. Detailed TEM investigations show that the film shows a layered structure with the majority of the top layer being the kesterite phase. Depending on the initial thin film composition, either about ~1 μm Cu-rich and Zn-poor kesterite or stoichiometric CZTS is formed as top layer. X-ray diffraction, Raman spectroscopy and transmission electron microscopy reveal the presence of Cu2−x S, ZnS and SnO2 minor secondary phases in the form of nanoinclusions or nanoparticles or intermediate layers. |
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 |
000426033400022 |
Publication Date |
2018-03-01 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1533-4880 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.483 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
Manoj Vishwakarma acknowl- edges IIT Delhi for MHRD fellowship. Professor B. R. Mehta acknowledges the support of the Schlumberger chair professorship. Manoj Vishwakarma, Joke Hadermann and Olesia M. karakulina acknowledge support provided by InsoL-DST. Manoj Vishwakarma acknowledges sup- port provided by CSIR funded projects and the support of DST-FIST Raman facility. References |
Approved |
Most recent IF: 1.483 |
Call Number |
EMAT @ emat @c:irua:147505 |
Serial |
4775 |
Permanent link to this record |
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Author |
Verchenko, V.Y.; Wei, Z.; Tsirlin, A.A.; Callaert, C.; Jesche, A.; Hadermann, J.; Dikarev, E.V.; Shevelkov, A.V. |
Title |
Crystal growth of the Nowotny chimney ladder phase Fe2Ge3 : exploring new Fe-based narrow-gap semiconductor with promising thermoelectric performance |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
29 |
Issue |
23 |
Pages |
9954-9963 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('A new synthetic approach based on chemical transport reactions has been introduced to obtain the Nowotny chimney ladder phase Fe2Ge3 in the form of single crystals and polycrystalline powders. The single crystals possess the stoichiometric composition and the commensurate chimney ladder structure of the Ru2Sn3 type in contrast to the polycrystalline samples that are characterized by a complex microstructure. In compliance with the 18-n electron counting rule formulated for T-E intermetallics, electronic structure calculations reveal a narrow-gap semiconducting behavior of Fe2Ge3 favorable for high thermoelectric performance. Measurements of transport and thermoelectric properties performed on the polycrystalline samples confirm the formation of a narrow band gap of similar to 30 meV and reveal high absolute values of the Seebeck coefficient at elevated temperatures. Low glass-like thermal conductivity is observed in a wide temperature range that might be caused by the underlying complex microstructure.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Chemical Society |
Place of Publication |
Washington, D.C |
Editor |
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Language |
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Wos |
000418206600013 |
Publication Date |
2017-11-14 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
11 |
Open Access |
OpenAccess |
Notes |
; The authors thank Dr. Sergey Kazakov and Oleg Tyablikov for their help with the PXRD experiments. V.Y.V. appreciates the help of Dr. Sergey Dorofeev in provision and handling of the Mo(CO)<INF>6</INF> reagent. The work is supported by the Russian Science Foundation, Grant No. 17-13-01033. V.Y.V. appreciates the support from the European Regional Development Fund, Project No. TK134. A.A.T. acknowledges financial support by the Federal Ministry for Education and Research under the Sofia Kovalevskaya Award of the Alexander von Humboldt Foundation. E.V.D. thanks the National Science Foundation, Grant No. CHE-1152441. C.C. acknowledges the support from the University of Antwerp through the BOF Grant No. 31445. ; |
Approved |
Most recent IF: 9.466 |
Call Number |
UA @ lucian @ c:irua:148531 |
Serial |
4869 |
Permanent link to this record |
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Author |
Augustyns, V.; van Stiphout, K.; Joly, V.; Lima, T.A.L.; Lippertz, G.; Trekels, M.; Menendez, E.; Kremer, F.; Wahl, U.; Costa, A.R.G.; Correia, J.G.; Banerjee, D.; Gunnlaugsson, H.P.; von Bardeleben, J.; Vickridge, I.; Van Bael, M.J.; Hadermann, J.; Araujo, J.P.; Temst, K.; Vantomme, A.; Pereira, L.M.C. |
Title |
Evidence of tetragonal distortion as the origin of the ferromagnetic ground state in gamma-Fe nanoparticles |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
96 |
Issue |
17 |
Pages |
174410 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('gamma-Fe and related alloys are model systems of the coupling between structure and magnetism in solids. Since different electronic states (with different volumes and magnetic ordering states) are closely spaced in energy, small perturbations can alter which one is the actual ground state. Here, we demonstrate that the ferromagnetic state of gamma-Fe nanoparticles is associated with a tetragonal distortion of the fcc structure. Combining a wide range of complementary experimental techniques, including low-temperature Mossbauer spectroscopy, advanced transmission electron microscopy, and synchrotron radiation techniques, we unambiguously identify the tetragonally distorted ferromagnetic ground state, with lattice parameters a = 3.76(2) angstrom and c = 3.50(2) angstrom, and a magnetic moment of 2.45(5) mu(B) per Fe atom. Our findings indicate that the ferromagnetic order in nanostructured gamma-Fe is generally associated with a tetragonal distortion. This observation motivates a theoretical reassessment of the electronic structure of gamma-Fe taking tetragonal distortion into account.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000414525200005 |
Publication Date |
2017-11-07 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
; The authors thank the Fund for Scientific Research-Flanders, the Concerted Research Action of the KU Leuven (GOA/14/007), the KU Leuven BOF (STRT/14/002), the Hercules Foundation, the Portuguese Foundation for Science and Technology (CERN/FIS-NUC/0004/2015), and the European Union Seventh Framework through ENSAR2 (European Nuclear Science and Applications Research, Project No. 654002), and SPIRIT (Support of Public and Industrial Research Using Ion Beam Technology, Contract No. 227012). We acknowledge the European Synchrotron Radiation Facility (ESRF) for providing beam time (experiments 26-01-1018, 26-01-1057, 20-02-728, HC-1850, HC-2208), as well as C. Baehtz, N. Boudet, and N. Blancand for support during the experiments. We acknowledge the ISOLDE-CERN facility for providing beam time (experiment IS580) and technical assistance. The authors (L.M.C.P., F.K.) acknowledge the facilities and the scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility at the Centre for Advanced Microscopy, Australian National University. We also acknowledge the contribution of Prof. Mark Ridgway (Australian National University), who passed away before the work was completed. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:147387 |
Serial |
4873 |
Permanent link to this record |
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Author |
Savina, A.A.; Morozov, V.A.; Buzlukov, A.L.; Arapova, I.Y.; Stefanovich, S.Y.; Baklanova, Y.V.; Denisova, T.A.; Medvedeva, N.I.; Bardet, M.; Hadermann, J.; Lazoryak, B.I.; Khaikina, E.G. |
Title |
New solid electrolyte Na9Al(MoO4)6 : structure and Na+ ion conductivity |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
29 |
Issue |
20 |
Pages |
8901-8913 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('Solid electrolytes are important materials with a wide range of technological applications. This work reports the crystal structure and electrical properties of a new solid electrolyte Na9Al(MoO4)(6). The monoclinic Na9Al(MoO4)(6) consists of isolated polyhedral, [Al(MoO4)(6)](9-) clusters composed of a central AlO6 octahedron sharing vertices with six MoO4 tetrahedra to form a three-dimensional framework. The AlO6 octahedron also shares edges with one NalO(6) octahedron and two Na2O(6) octahedra. Na3-Na5 atoms are located in the framework cavities. The structure is related to that of sodium ion conductor II-Na3Fe2(AsO4)(3). High-temperature conductivity measurements revealed that the conductivity (sigma) of Na9Al(MoO4)(6) at 803 K equals 1.63 X 10(-2) S cm(-1). The temperature behavior of the Na-23 and Al-27 nuclear magnetic resonance spectra and the spin-lattice relaxation rates of the Na-23 nuclei indicate the presence of fast Na+ ion diffusion in the studied compound. At T\u003C490 K, diffusion occurs by means of Na+ ion jumps exclusively through the sublattice of Na3-Na5 positions, whereas Na1 and Na2 become involved in the diffusion processes (through chemical exchange with the Na3-Na5 sublattice) only at higher temperatures.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Chemical Society |
Place of Publication |
Washington, D.C |
Editor |
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Language |
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Wos |
000413884900037 |
Publication Date |
2017-09-26 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
13 |
Open Access |
OpenAccess |
Notes |
; The research was performed within the state assignment of FASO of Russia (Themes 01201463330, A16-116122810214-9, and 0339-2016-0007), supported in part by the Russian Foundation for Basic Research (Projects 16-03-00510, 16-03-00164, and 17-03-00333). ; |
Approved |
Most recent IF: 9.466 |
Call Number |
UA @ lucian @ c:irua:147432 |
Serial |
4886 |
Permanent link to this record |
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Author |
Sanchez-Barriga, J.; Ogorodnikov, I.I.; Kuznetsov, M.V.; Volykhov, A.A.; Matsui, F.; Callaert, C.; Hadermann, J.; Verbitskiy, N.I.; Koch, R.J.; Varykhalov, A.; Rader, O.; Yashina, L.V. |
Title |
Observation of hidden atomic order at the interface between Fe and topological insulator Bi2Te3 |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
19 |
Issue |
45 |
Pages |
30520-30532 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
<script type='text/javascript'>document.write(unpmarked('To realize spintronic devices based on topological insulators (TIs), well-defined interfaces between magnetic metals and TIs are required. Here, we characterize atomically precisely the interface between the 3d transition metal Fe and the TI Bi2Te3 at different stages of its formation. Using photoelectron diffraction and holography, we show that after deposition of up to 3 monolayers Fe on Bi2Te3 at room temperature, the Fe atoms are ordered at the interface despite the surface disorder revealed by our scanning-tunneling microscopy images. We find that Fe occupies two different sites: a hollow adatom deeply relaxed into the Bi2Te3 quintuple layers and an interstitial atom between the third (Te) and fourth (Bi) atomic layers. For both sites, our core-level photoemission spectra and density-functional theory calculations demonstrate simultaneous chemical bonding of Fe to both Te and Bi atoms. We further show that upon deposition of Fe up to a thickness of 20 nm, the Fe atoms penetrate deeper into the bulk forming a 2-5 nm interface layer containing FeTe. In addition, excessive Bi is pushed down into the bulk of Bi2Te3 leading to the formation of septuple layers of Bi3Te4 within a distance of similar to 25 nm from the interface. Controlling the magnetic properties of the complex interface structures revealed by our work will be of critical importance when optimizing the efficiency of spin injection in TI-based devices.')); |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000416054400023 |
Publication Date |
2017-10-24 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
4 |
Open Access |
OpenAccess |
Notes |
; The authors acknowledge financial support within the bilateral program “Russian-German Laboratory at BESSY II” and thank Helmholtz Zentrum Berlin for granting access to the beamlines RGBL, UE112-PGM2a and U49-PGM1. The Supercomputing Center of Lomonosov Moscow State University is gratefully acknowledged for granting access to the “Lomonosov” supercomputer. The work was partially supported by DFG priority program SPP 1666, Impuls- und Vernetzungsfonds der Helmholtz-Gemeinschaft (Grant No. HRJRG-408) and Russian Foundation for Basic Research (Grants No. 13-02-91327 and No. 16-29-06410). C. C. acknowledges support from the University of Antwerp through the BOF grant 31445. The authors thank Dr Vera Neudachina, Daria Tsukanova, Dr Elmar Kataev and Dr Maria Batuk for their support during the XPS and TEM experiments. ; |
Approved |
Most recent IF: 4.123 |
Call Number |
UA @ lucian @ c:irua:147659 |
Serial |
4888 |
Permanent link to this record |
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Author |
Ulu Okudur, F.; D'Haen, J.; Vranken, T.; De Sloovere, D.; Verheijen, M.; Karakulina, O.M.; Abakumov, A.M.; Hadermann, J.; Van Bael, M.K.; Hardy, A. |
Title |
Ti surface doping of LiNi0.5Mn1.5O4−δpositive electrodes for lithium ion batteries |
Type |
A1 Journal article |
Year |
2018 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
Volume |
8 |
Issue |
13 |
Pages |
7287-7300 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The particle surface of LiNi0.5Mn1.5O4−δ (LNMO), a Li-ion battery cathode material, has been modified by Ti cation doping through a hydrolysis–condensation reaction followed by annealing in oxygen. The effect of different annealing temperatures (500–850 °C) on the Ti distribution and electrochemical performance of the surface modified LNMO was investigated. Ti cations diffuse from the preformed amorphous ‘TiOx’ layer into the LNMO surface during annealing at 500 °C. This results in a 2–4 nm thick Ti-rich spinel surface having lower Mn and Ni content compared to the core of the LNMO particles, which was observed with scanning transmission electron microscopy coupled with compositional EDX mapping. An increase in the annealing temperature promotes the formation of a Ti bulk doped LiNi(0.5−w)Mn(1.5+w)−tTitO4 phase and Ti-rich LiNi0.5Mn1.5−yTiyO4 segregates above 750 °C. Fourier-transform infrared spectrometry indicates increasing Ni–Mn ordering with annealing temperature, for both bare and surface modified LNMO. Ti surface modified LNMO annealed at 500 °C shows a superior cyclic stability, coulombic efficiency and rate performance compared to bare LNMO annealed at 500 °C when cycled at 3.4–4.9 V vs. Li/Li+. The improvements are probably due to suppressed Ni and Mn dissolution with Ti surface doping. |
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 |
000425508900064 |
Publication Date |
2018-02-13 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2046-2069 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.108 |
Times cited |
9 |
Open Access |
OpenAccess |
Notes |
This research is supported by the Research Foundation Flanders (FWO Vlaanderen, grant number G040116N). This project receives the support of the European Union, the European Regional Development Fund ERDF, Flanders Innovation & Entrepreneurship and the Province of Limburg (project 936). Greet Cuyvers and Gilles Bonneux (UHasselt) are acknowledged for the ICP-AES sample preparation and measurements. Vera Meynen and Karen Leyssens (Antwerp University, Belgium) are acknowledged for the BET measurements. Special thanks to Bart Ruttens (UHasselt) for XRD measurements and discussions on the refinements. |
Approved |
Most recent IF: 3.108 |
Call Number |
EMAT @ emat @c:irua:149513 |
Serial |
4905 |
Permanent link to this record |
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Author |
Sathiya, M.; Jacquet, Q; Doublet, M.L; Karakulina, O.M.; Hadermann, J.; Tarascon, J.-M. |
Title |
A Chemical Approach to Raise Cell Voltage and Suppress Phase Transition in O3 Sodium Layered Oxide Electrodes |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Advanced energy materials |
Abbreviated Journal |
Adv. Energy Mater. |
Volume |
|
Issue |
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Pages |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Sodium ion batteries (NIBs) are one of the versatile technologies for lowcost rechargeable batteries. O3-type layered sodium transition metal oxides (NaMO2, M = transition metal ions) are one of the most promising positive electrode materials considering their capacity. However, the use of O3 phases is limited due to their low redox voltage and associated multiple phase transitions which are detrimental for long cycling. Herein, a simple strategy is proposed to successfully combat these issues. It consists of the introduction of a larger, nontransition metal ion Sn4+ in NaMO2 to prepare a series of NaNi0.5Mn0.5−y SnyO2 (y = 0–0.5) compositions with attractive electrochemical performances, namely for y = 0.5, which shows a single-phase transition from O3 ⇔ P3 at the very end of the oxidation process. Na-ion NaNi0.5Sn0.5O2/C coin cells are shown to deliver an average cell voltage of 3.1 V with an excellent capacity retention as compared to an average stepwise voltage of ≈2.8 V and limited capacity retention for the pure NaNi0.5Mn0.5O2 phase. This study potentially shows the way to manipulate the O3 NaMO2 for facilitating their practical use in NIBs. |
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 |
000430163100013 |
Publication Date |
2018-01-11 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
21.875 |
Times cited |
28 |
Open Access |
OpenAccess |
Notes |
M.S. and Q.J. contributed equally to this work. The authors thank Dr. Daniel Alves Dalla Corte and Sujoy Saha for electronic conductivity measurements and Prof. Dominique Larcher for fruitful discussions. Q.J. thanks the ANR “Deli-Redox” for Ph.D. funding. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. TGA analysis by Matthieu Courty, LRCS, Amiens, is greatly acknowledged. J.H. and O.M.K. acknowledge funding from FWO Vlaanderen project G040116N. |
Approved |
Most recent IF: NA |
Call Number |
EMAT @ emat @c:irua:149515 |
Serial |
4907 |
Permanent link to this record |
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Author |
Chin, C.-M.; Battle, P.D.; Blundell, S.J.; Hunter, E.; Lang, F.; Hendrickx, M.; Sena, R.P.; Hadermann, J. |
Title |
Comparative study of the magnetic properties of La3Ni2B'O9 for B' = Nb, Ta or Sb |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
258 |
Issue |
258 |
Pages |
825-834 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Polycrystalline samples of La3Ni2NbO9 and La3Ni2TaO9 have been characterised by X-ray and neutron diffraction, electron microscopy, magnetometry and muon spin relaxation (mu SR); the latter technique was also applied to La3Ni2SbO9. On the length scale of a neutron diffraction experiment, the six-coordinate sites of the monoclinic perovskite structure are occupied in a 1:1 ordered manner by Ni and a random 1/3Ni/2/3B' mixture. Electron microscopy demonstrated that this 1:1 ordering is maintained over microscopic distances, although diffuse scattering indicative of short-range ordering on the mixed site was observed. No magnetic Bragg scattering was observed in neutron diffraction patterns collected from La3Ni2B'O-9 (B' = Nb or Ta) at 5 K although in each case mu SR identified the presence of static spins below 30 K. Magnetometry showed that La3Ni2NbO9 behaves as a spin glass below 29 K but significant short-range interactions are present in La3Ni2NbO9 below 85 K. The contrasting properties of these compounds are discussed in terms of their microstructure. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000423650400107 |
Publication Date |
2017-12-20 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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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 |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
6 |
Open Access |
Not_Open_Access |
Notes |
; We thank EPSRC for funding through Grants EP/M0189541 and EP/N023803. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful E. Suard for experimental assistance at ILL. ; |
Approved |
Most recent IF: 2.299 |
Call Number |
UA @ lucian @ c:irua:149284 |
Serial |
4928 |
Permanent link to this record |
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Author |
Istomin, S.Y.; Morozov, A.V.; Abdullayev, M.M.; Batuk, M.; Hadermann, J.; Kazakov, S.M.; Sobolev, A.V.; Presniakov, I.A.; Antipov, E.V. |
Title |
High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-\delta perovskites as prospective electrode materials for symmetrical SOFC |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
258 |
Issue |
258 |
Pages |
1-10 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
La1-yCayFe0.5+x(Mg,Mo)(0.5-x)O3-delta oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mossbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-delta and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-delta) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-delta is oxygen deficient with delta approximate to 0.15. Oxides are stable in reducing atmosphere (Ar/H-2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1-xGdxO2-x/2 electrolyte mixtures treated at 1173-1373K, while Fe-rich compositions (x >= 0.1) react with Zr1-xYxO2-x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4-12.7 ppm K-1. In reducing atmosphere their TECs were found to increase up to 12.1-15.4 ppm K-1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H-2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000423650400001 |
Publication Date |
2017-10-11 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
Not_Open_Access |
Notes |
; This work was financially supported by Russian Science Foundation (project number 16-13-10327). ; |
Approved |
Most recent IF: 2.299 |
Call Number |
UA @ lucian @ c:irua:149283 |
Serial |
4936 |
Permanent link to this record |
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|
|
Author |
Garud, S.; Gampa, N.; Allen, T.G.; Kotipalli, R.; Flandre, D.; Batuk, M.; Hadermann, J.; Meuris, M.; Poortmans, J.; Smets, A.; Vermang, B. |
Title |
Surface passivation of CIGS solar cells using gallium oxide |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
Volume |
215 |
Issue |
7 |
Pages |
1700826 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
This work proposes gallium oxide grown by plasma-enhanced atomic layer deposition, as a surface passivation material at the CdS buffer interface of Cu(In,Ga)Se-2 (CIGS) solar cells. In preliminary experiments, a metal-insulator-semiconductor (MIS) structure is used to compare aluminium oxide, gallium oxide, and hafnium oxide as passivation layers at the CIGS-CdS interface. The findings suggest that gallium oxide on CIGS may show a density of positive charges and qualitatively, the least interface trap density. Subsequent solar cell results with an estimated 0.5nm passivation layer show an substantial absolute improvement of 56mV in open-circuit voltage (V-OC), 1mAcm(-2) in short-circuit current density (J(SC)), and 2.6% in overall efficiency as compared to a reference (with the reference showing 8.5% under AM 1.5G). |
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 |
000430128500015 |
Publication Date |
2018-02-27 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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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 |
Not_Open_Access |
Notes |
; The work published in this paper was supported by the European Research Council (ERC) under the Union's Horizon 2020 research and innovation programme (grant agreement No 715027). The authors would also like to thank Dr. Marcel Simor (Solliance) for the CIGS layer fabrication and Prof. Johan Lauwaert (Universtiy of Ghent) for his guidance on DLTS measurements. ; |
Approved |
Most recent IF: 1.775 |
Call Number |
UA @ lucian @ c:irua:150761 |
Serial |
4981 |
Permanent link to this record |
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|
|
Author |
Pearce, P.E.; Rousse, G.; Karakulina, O.M.; Hadermann, J.; Van Tendeloo, G.; Foix, D.; Fauth, F.; Abakumov, A.M.; Tarascon, J.-M. |
Title |
β-Na1.7IrO3: A Tridimensional Na-Ion Insertion Material with a Redox Active Oxygen Network |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
30 |
Issue |
10 |
Pages |
3285-3293 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The revival of the Na-ion battery concept has prompted an intense search for new high capacity Na-based positive electrodes. Recently, emphasis has been placed on manipulating Na-based layered compounds to trigger the participation of the anionic network. We further explored this direction and show the feasibility of achieving anionic-redox activity in three-dimensional Na-based compounds. A new 3D β-Na1.7IrO3 phase was synthesized in a two-step process, which involves first the electrochemical removal of Li from β-Li2IrO3 to produce β-IrO3, which is subsequently reduced by electrochemical Na insertion. We show that β-Na1.7IrO3 can reversibly uptake nearly 1.3 Na+ per formula unit through an uneven voltage profile characterized by the presence of four plateaus related to structural transitions. Surprisingly, the β-Na1.7IrO3 phase was found to be stable up to 600 °C, while it could not be directly synthesized via conventional synthetic methods. Although these Na-based iridate phases are of limited practical interest, they help to understand how introducing highly polarizable guest ions (Na+) into host rocksalt-derived oxide structures affects the anionic redox mechanism. |
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 |
000433403800014 |
Publication Date |
2018-05-22 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
6 |
Open Access |
OpenAccess |
Notes |
The authors thank A. Perez for fruitful discussions and his valuable help in synchrotron XRD experiment and Matthieu Courty for carrying out the DSC measurements. The authors also greatly thank Matthieu Saubanère and Marie-Liesse Doublet for valuable discussions on theoretical aspects of this work. This work is based on experiments performed on the Materials Science and Powder Diffraction Beamline at ALBA synchrotron (Proposal 2016091814), Cerdanyola del Vallès, E- 08290 Barcelona, Spain. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant- Project 670116-ARPEMA. G.R. acknowledges funding from ANR DeliRedox. O.M.K., J.H., and A.M.A. are grateful to FWO Vlaanderen for financial support under Grant G040116N. |
Approved |
Most recent IF: 9.466 |
Call Number |
EMAT @ emat @c:irua:152048 |
Serial |
4996 |
Permanent link to this record |
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|
|
Author |
Hasanli, N.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Hayward, M.A. |
Title |
Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5 |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
Volume |
47 |
Issue |
44 |
Pages |
15783-15790 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments. |
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 |
000450208000019 |
Publication Date |
2018-10-18 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1477-9226 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
4.029 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC. NH acknowledges funding from the “State Programme on Education of Azerbaijani Youth Abroad in 2007-2015” by the Ministry of Education of Azerbaijan. J. V. and N. G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. |
Approved |
Most recent IF: 4.029 |
Call Number |
EMAT @ emat @c:irua:155771 |
Serial |
5137 |
Permanent link to this record |
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|
Author |
Vishwakarma, M.; Thota, N.; Karakulina, O.; Hadermann, J.; Mehta, B.R. |
Title |
Role of graphene inter layer on the formation of the MoS2 – CZTS interface during growth |
Type |
P1 Proceeding |
Year |
2018 |
Publication |
(icc-2017) |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
|
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT) |
Abstract |
The growth of MoS2 layer near the Mo/CZTS interface during sulphurization process can have an impact on back contact cell parameters (series resistance and fill factor) depending upon the thickness or quality of MoS2. This study reports the dependence of the thickness of interfacial MoS2 layer on the growth of graphene at the interface between molybdenum back contact and deposited CZTS layer. The graphene layer reduces the accumulation of Zn/ZnS, Sn/SnO2 and formation of pores near the MoS2-CZTS interface. The use of graphene as interface layer can be potentially useful for improving the quality of Mo/MoS2/CZTS interface. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Amer inst physics |
Place of Publication |
Melville |
Editor |
|
Language |
|
Wos |
000436313003046 |
Publication Date |
2018-05-09 |
Series Editor |
|
Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
|
Series Volume |
1953 |
Series Issue |
|
Edition |
|
ISSN |
978-0-7354-1648-2; 0094-243x; 0094-243x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
; The authors acknowledge support provided by DST project. M.V. acknowledges IIT Delhi for MHRD fellowship. Prof. B. R. Mehta acknowledges the support of the Schlumberger chair professorship. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:153203 |
Serial |
5126 |
Permanent link to this record |
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Author |
Morozov, V.; Deyneko, D.; Basoyich, O.; Khaikina, E.G.; Spassky, D.; Morozov, A.; Chernyshev, V.; Abakumov, A.; Hadermann, J. |
Title |
Incommensurately modulated structures and luminescence properties of the AgxSm(2-x)/3WO4 (x=0.286, 0.2) scheelites as thermographic phosphors |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
30 |
Issue |
14 |
Pages |
4788-4798 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Ag+ for Sm3+ substitution in the scheelite-type AgxSm(2-x)/3 square(1-2x)/3WO4 tungstates has been investigated for its influence on the cation-vacancy ordering and luminescence properties. A solid state method was used to synthesize the x = 0.286 and x = 0.2 compounds, which exhibited (3 + 1)D incommensurately modulated structures in the transmission electron microscopy study. Their structures were refined using high resolution synchrotron powder X-ray diffraction data. Under near-ultraviolet light, both compounds show the characteristic emission lines for (4)G(5/2) -> H-6(J) (J = 5/2, 7/2, 9/2, and 11/2) transitions of the Sm3+ ions in the range 550-720 nm, with the J = 9/2 transition at the similar to 648 nm region being dominant for all photoluminescence spectra. The intensities of the (4)G(5/2) -> H-6(9/2) and (4)G(5/2) -> H-6(7/2) bands have different temperature dependencies. The emission intensity ratios (R) for these bands vary reproducibly with temperature, allowing the use of these materials as thermographic phosphors. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Chemical Society |
Place of Publication |
Washington, D.C |
Editor |
|
Language |
|
Wos |
000440105500037 |
Publication Date |
2018-06-21 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
2 |
Open Access |
Not_Open_Access |
Notes |
; This research was supported by FWO (Project G039211N), Flanders Research Foundation. The research was carried out within the state assignment of FASO of Russia (Themes No. 0339-2016-0007). V.M. thanks the Russian Foundation for Basic Research (Grant 18-03-00611) for financial support. E.G.K. and O.B. acknowledge financial support from the Russian Foundation for Basic Research (Grant 16-03-00510). D.D. thanks the Foundation of the Russian Federation President (Grant MK-3502.2018.5) for financial support. We are grateful to the ESRF for granting the beamtime. V.C. is grateful for the financial support of the Russian Ministry of Science and Education (Project No. RFMEFI61616X0069). We are grateful to the ESRF for the access to ID22 station (experiment MA-3313). ; |
Approved |
Most recent IF: 9.466 |
Call Number |
UA @ lucian @ c:irua:153156 |
Serial |
5107 |
Permanent link to this record |
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|
|
Author |
Tang, Y.; Hunter, E.C.; Battle, P.D.; Hendrickx, M.; Hadermann, J.; Cadogan, J.M. |
Title |
Ferrimagnetism as a consequence of unusual cation ordering in the Perovskite SrLa2FeCoSbO9 |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
57 |
Issue |
12 |
Pages |
7438-7445 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A polycrystalline sample of SrLa2FeCoSbO9 has been prepared in a solid-state reaction and studied by a combination of electron microscopy, magnetometry, Mossbauer spectroscopy, X-ray diffraction, and neutron diffraction. The compound adopts a monoclinic (space group P2(1)/n; a = 5.6218(6), b = 5.6221(6), c = 7.9440(8) angstrom, beta = 90.050(7)degrees at 300 K) perovskite-like crystal structure with two crystallographically distinct six-coordinate sites. One of these sites is occupied by 2/3 Co-2(+),1/3 Fe3+ and the other by 2/3 Sb5+, 1/3 Fe3+. This pattern of cation ordering results in a transition to a ferrimagnetic phase at 215 K. The magnetic moments on nearest-neighbor, six-coordinate cations align in an antiparallel manner, and the presence of diamagnetic Sb5+ on only one of the two sites results in a nonzero remanent magnetization of similar to 1 mu(B) per formula unit at 5 K. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000436023800073 |
Publication Date |
2018-05-29 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
6 |
Open Access |
Not_Open_Access |
Notes |
; PDB, ECH, and JH acknowledge support from EPSRC under grant EP/M0189954/1. We would like to thank the STFC for the award of beamtime at the ISIS Neutron and Muon Source (RB 1610100), and we thank Dr. I. da Silva for the assistance provided. We also thank Dr. R Paria Sena for help with the HAADF-STEM and STEM-EDX experiments. ; |
Approved |
Most recent IF: 4.857 |
Call Number |
UA @ lucian @ c:irua:152485 |
Serial |
5103 |
Permanent link to this record |
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|
|
Author |
Malkov, I., V; Krivetskii, V.V.; Potemkin, D., I; Zadesenets, A., V; Batuk, M.M.; Hadermann, J.; Marikutsa, A., V; Rumyantseva, M.N.; Gas'kov, A.M. |
Title |
Effect of Bimetallic Pd/Pt Clusters on the Sensing Properties of Nanocrystalline SnO2 in the Detection of CO |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Russian journal of inorganic chemistry |
Abbreviated Journal |
Russ J Inorg Chem+ |
Volume |
63 |
Issue |
8 |
Pages |
1007-1011 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanocrystalline tin dioxide modified by Pd and Pt clusters or by bimetallic PdPt nanoparticles was synthesized. Distribution of the modifers on the SnO2 surface was studied by high-resolution transmission electron microscopy and energy dispersive X-ray microanalysis with element distribution mapping. It was shown that the Pd/Pt ratio in bimetallic particles varies over a broad range and does not depend on the particle diameter. The effect of platinum metals on the reducibility of nanocrystalline SnO2 by hydrogen was determined. The sensing properties of the resulting materials towards 6.7 ppm CO in air were estimated in situ by electrical conductivity measurements. The sensor response of SnO2 modified with bimetallic PdPt particles was a superposition of the signals of samples with Pt and Pd clusters. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000442749500003 |
Publication Date |
2018-08-25 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0036-0236 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.787 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
; This work was supported by the ERA.Net RUS Plus program (project 096 FONSENS, RFBR grant 16-53-76001). ; |
Approved |
Most recent IF: 0.787 |
Call Number |
UA @ lucian @ c:irua:153752 |
Serial |
5092 |
Permanent link to this record |
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Author |
Cassidy, S.J.; Orlandi, F.; Manuel, P.; Hadermann, J.; Scrimshire, A.; Bingham, P.A.; Clarke, S.J. |
Title |
Complex Magnetic Ordering in the Oxide Selenide Sr2Fe3Se2O3 |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
57 |
Issue |
16 |
Pages |
10312-10322 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000442489100078 |
Publication Date |
2018-07-31 |
Series Editor |
|
Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
2 |
Open Access |
OpenAccess |
Notes |
; S. J. Cassidy prepared the samples and performed the diffraction and magnetometry measurements. F.O., P.M., and S. J. Cassidy measured and interpreted the NPD data. J.H. performed and interpreted the electron diffraction measurements. A.S. and P.A.B. performed and interpreted the Mossbauer spectroscopy measurements. S. J. Cassidy and S. J. Clarke conceived the project and wrote the paper with input from all co-authors. We acknowledge the financial support of the EPSRC (Grants EP/I017844/1, EP/P018874/1, and EP/ M020517/1), and the Leverhulme Trust (RPG-2014-221). We thank the ESTEEM2 network for enabling the electron microscopy investigations, the ISIS facility for the award of beamtime on WISH (RB1610357), and the Diamond Light Source Ltd. for the award of beam time on I11 (allocation EE13284). We thank Dr. C. Murray, Dr. S. Day and Dr. A. Baker for assistance on I11 and Dr. M. Coduri and Dr. A. N. Fitch for assistance on ID22. ; |
Approved |
Most recent IF: 4.857 |
Call Number |
UA @ lucian @ c:irua:153723 |
Serial |
5085 |
Permanent link to this record |
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|
|
Author |
Volykhov, A.A.; Sanchez-Barriga, J.; Batuk, M.; Callaert, C.; Hadermann, J.; Sirotina, A.P.; Neudachina, V.S.; Belova, A.I.; Vladimirova, N.V.; Tamm, M.E.; Khmelevsky, N.O.; Escudero, C.; Perez-Dieste, V.; Knop-Gericke, A.; Yashina, L.V. |
Title |
Can surface reactivity of mixed crystals be predicted from their counterparts? A case study of (Bi1-xSbx)2Te3 topological insulators |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
Volume |
6 |
Issue |
33 |
Pages |
8941-8949 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The behavior of ternary mixed crystals or solid solutions and its correlation with the properties of their binary constituents is of fundamental interest. Due to their unique potential for application in future information technology, mixed crystals of topological insulators with the spin-locked, gapless states on their surfaces attract huge attention of physicists, chemists and material scientists. (Bi1-xSbx)(2)Te-3 solid solutions are among the best candidates for spintronic applications since the bulk carrier concentration can be tuned by varying x to obtain truly bulk-insulating samples, where the topological surface states largely contribute to the transport and the realization of the surface quantum Hall effect. As this ternary compound will be evidently used in the form of thin-film devices its chemical stability is an important practical issue. Based on the atomic resolution HAADF-TEM and EDX data together with the XPS results obtained both ex situ and in situ, we propose an atomistic picture of the mixed crystal reactivity compared to that of its binary constituents. We find that the surface reactivity is determined by the probability of oxygen attack on the Te-Sb bonds, which is directly proportional to the number of Te atoms bonded to at least one Sb atom. The oxidation mechanism includes formation of an amorphous antimony oxide at the very surface due to Sb diffusion from the first two quintuple layers, electron tunneling from the Fermi level of the crystal to oxygen, oxygen ion diffusion to the crystal, and finally, slow Te oxidation to the +4 oxidation state. The oxide layer thickness is limited by the electron transport, and the overall process resembles the Cabrera-Mott mechanism in metals. These observations are critical not only for current understanding of the chemical reactivity of complex crystals, but also to improve the performance of future spintronic devices based on topological materials. |
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 |
000443279300007 |
Publication Date |
2018-07-20 |
Series Editor |
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Series Title ![sorted by Series Title field, descending order (down)](img/sort_desc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2050-7526; 2050-7534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.256 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
; The authors acknowledge financial support within the bilateral program "Russian-German Laboratory at BESSY II''. We thank Helmholtz-Zentrum Berlin for granting access to the beamlines RGBL, UE112-PGM2a and ISISS. Support of ALBA staff during measurements at the CIRCE beamline is gratefully acknowledged. We thank Dr Ivan Bobrikov for support in the XRD measurements and Daria Tsukanova for the participation in crystal preparation and XPS measurements. A. Volykhov thanks RSF (grant 18-73-00248) for financial support. A. I. Belova acknowledges support from the G-RISC Centre of Excellence. The work was supported by Helmholtz Gemeinschaft (Grant No. HRJRG-408) and RFBR (grant 14-03-31518). J. H. and C. C. acknowledge support from the University of Antwerp through the BOF grant 31445. ; |
Approved |
Most recent IF: 5.256 |
Call Number |
UA @ lucian @ c:irua:153647 |
Serial |
5080 |
Permanent link to this record |
|
|
|
Author |
Guzzinati, G.; Altantzis, T.; Batuk, M.; De Backer, A.; Lumbeeck, G.; Samaee, V.; Batuk, D.; Idrissi, H.; Hadermann, J.; Van Aert, S.; Schryvers, D.; Verbeeck, J.; Bals, S. |
Title |
Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Materials |
Abbreviated Journal |
Materials |
Volume |
11 |
Issue |
11 |
Pages |
1304 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science. |
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Wos |
000444112800041 |
Publication Date |
2018-07-28 |
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ISSN |
1996-1944 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.654 |
Times cited |
15 |
Open Access |
OpenAccess |
Notes |
Fonds Wetenschappelijk Onderzoek, G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N AUHA13009 ; European Research Council, COLOURATOM 335078 ; Universiteit Antwerpen, GOA Solarpaint ; G. Guzzinati, T. Altantzis and A. De Backer have been supported by postdoctoral fellowship grants from the Research Foundation Flanders (FWO). Funding was also received from the European Research Council (starting grant no. COLOURATOM 335078), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 770887), the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N, G.0401.16N) and from the University of Antwerp through GOA project Solarpaint. Funding for the TopSPIN precession system under grant AUHA13009, as well as for the Qu-Ant-EM microscope, is acknowledged from the HERCULES Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (F.R.S.-FNRS). (ROMEO:green; preprint:; postprint:can ; pdfversion:can); saraecas; ECAS_Sara; |
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Most recent IF: 2.654 |
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EMAT @ emat @c:irua:153737UA @ admin @ c:irua:153737 |
Serial |
5064 |
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Author |
Karakulina, O.M.; Demortière, A.; Dachraoui, W.; Abakumov, A.M.; Hadermann, J. |
Title |
In Situ Electron Diffraction Tomography Using a Liquid-Electrochemical Transmission Electron Microscopy Cell for Crystal Structure Determination of Cathode Materials for Li-Ion batteries |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
18 |
Issue |
10 |
Pages |
6286-6291 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
We demonstrate that changes in the unit cell structure of lithium battery cathode materials during electrochemical cycling in liquid electrolyte can be determined for particles of just a few hundred nanometers in size using in situ transmission electron microscopy (TEM). The atomic coordinates, site occupancies (including lithium occupancy), and cell parameters of the materials can all be reliably quantified. This was achieved using electron diffraction tomography (EDT) in a sealed electrochemical cell with conventional liquid electrolyte (LP30) and LiFePO4 crystals, which have a well-documented charged structure to use as reference. In situ EDT in a liquid environment cell provides a viable alternative to in situ X-ray and neutron diffraction experiments due to the more local character of TEM, allowing for single crystal diffraction data to be obtained from multiphased powder samples and from submicrometer- to nanometer-sized particles. EDT is the first in situ TEM technique to provide information at the unit cell level in the liquid environment of a commercial TEM electrochemical cell. Its application to a wide range of electrochemical experiments in liquid environment cells and diverse types of crystalline materials can be envisaged. |
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000447355400024 |
Publication Date |
2018-10-10 |
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Edition |
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ISSN |
1530-6984 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.712 |
Times cited |
12 |
Open Access |
Not_Open_Access: Available from 08.09.2019
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Notes |
O.M. Karakulina, A.M. Abakumov and J. Hadermann acknowledge support from FWO under grant G040116N. A. Demortière wants to thank the French network on the electrochemical energy storage (RS2E), the Store-Ex Labex, for the financial support. Finally, the Fonds Européen de Développement Régional (FEDER), CNRS, Région Hauts-de-France, and Ministère de l’Education Nationale de l’Enseignement Supérieur et de la Recherche are acknowledged for funding. |
Approved |
Most recent IF: 12.712 |
Call Number |
EMAT @ emat @c:irua:154750 |
Serial |
5063 |
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Author |
Yang, C.; Batuk, M.; Jacquet, Q.; Rousse, G.; Yin, W.; Zhang, L.; Hadermann, J.; Abakumov, A.M.; Cibin, G.; Chadwick, A.; Tarascon, J.-M.; Grimaud, A. |
Title |
Revealing pH-Dependent Activities and Surface Instabilities for Ni-Based Electrocatalysts during the Oxygen Evolution Reaction |
Type |
A1 Journal article |
Year |
2018 |
Publication |
ACS energy letters |
Abbreviated Journal |
Acs Energy Lett |
Volume |
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Issue |
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Pages |
2884-2890 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Multiple electrochemical processes are involved at the catalyst/ electrolyte interface during the oxygen evolution reaction (OER). With the purpose of elucidating the complexity of surface dynamics upon OER, we systematically studied two Ni-based crystalline oxides (LaNiO3−δ and La2Li0.5Ni0.5O4) and compared them with the state-of-the-art Ni−Fe (oxy)- hydroxide amorphous catalyst. Electrochemical measurements such as rotating ring disk electrode (RRDE) and electrochemical quartz microbalance microscopy (EQCM) coupled with a series of physical characterizations including transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS) were conducted to unravel the exact pH effect on both the OER activity and the catalyst stability. We demonstrate that for Ni-based crystalline catalysts the rate for surface degradation depends on the pH and is greater than the rate for surface reconstruction. This behavior is unlike that for the amorphous Ni oxyhydroxide catalyst, which is found to be more stable and pH-independent. |
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Wos |
000453805100005 |
Publication Date |
2018-11-08 |
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ISSN |
2380-8195 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access: Available from 06.11.2019
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Notes |
C.Y., J.-M.T., and A.G. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC GrantProject 670116-ARPEMA. A.G. acknowledges financial support from the ANR MIDWAY (Project ID ANR-17-CE05- 0008). We acknowledge Diamond Light Source for time awarded to the Energy Materials BAG on Beamline B18, under Proposal sp12559. |
Approved |
Most recent IF: NA |
Call Number |
EMAT @ emat @c:irua:155046 |
Serial |
5067 |
Permanent link to this record |