Records |
Author |
Dubrovinsky, L.; Dubrovinskaia, N.; Prakapenka, V.B.; Abakumov, A.M. |
Title |
Implementation of micro-ball nanodiamond anvils for high-pressure studies above 6 Mbar |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
3 |
Issue |
|
Pages |
1163-1167 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Since invention of the diamond anvil cell technique in the late 1950s for studying materials at extreme conditions, the maximum static pressure generated so far at room temperature was reported to be about 400 GPa. Here we show that use of micro-semi-balls made of nanodiamond as second-stage anvils in conventional diamond anvil cells drastically extends the achievable pressure range in static compression experiments to above 600 GPa. Micro-anvils (10-50 mu m in diameter) of superhard nano-diamond (with a grain size below similar to 50 nm) were synthesized in a large volume press using a newly developed technique. In our pilot experiments on rhenium and gold we have studied the equation of state of rhenium at pressures up to 640 GPa and demonstrated the feasibility and crucial necessity of the in situ ultra high-pressure measurements for accurate determination of material properties at extreme conditions. |
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 |
000313514100073 |
Publication Date |
2012-10-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
150 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.124; 2012 IF: 10.015 |
Call Number |
UA @ lucian @ c:irua:110134 |
Serial |
1563 |
Permanent link to this record |
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Author |
Morozov, V.A.; Bertha, A.; Meert, K.W.; Van Rompaey, S.; Batuk, D.; Martinez, G.T.; Van Aert, S.; Smet, P.F.; Raskina, M.V.; Poelman, D.; Abakumov, A.M.; Hadermann, J.; |
Title |
Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
25 |
Issue |
21 |
Pages |
4387-4395 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, 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 luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000327045000030 |
Publication Date |
2013-09-24 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
63 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2013 IF: 8.535 |
Call Number |
UA @ lucian @ c:irua:112776 |
Serial |
1594 |
Permanent link to this record |
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Author |
Mordvinova, N.; Emelin, P.; Vinokurov, A.; Dorofeev, S.; Abakumov, A.; Kuznetsova, T. |
Title |
Surface processes during purification of InP quantum dots |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Beilstein journal of nanotechnology |
Abbreviated Journal |
Beilstein J Nanotech |
Volume |
5 |
Issue |
|
Pages |
1220-1225 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH)(3) during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of post-synthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular. |
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 |
000339912400002 |
Publication Date |
2014-08-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2190-4286; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.127 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.127; 2014 IF: 2.670 |
Call Number |
UA @ lucian @ c:irua:118748 |
Serial |
3397 |
Permanent link to this record |
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Author |
Kolchina, L. M.; Lyskov, N.V.; Kuznetsov, A.N.; Kazakov, S.M.; Galin, M.Z.; Meledin, A.; Abakumov, A.M.; Bredikhin, S.I.; Mazo, G.N.; Antipov, E.V. |
Title |
Evaluation of Ce-doped Pr2CuO4for potential application as a cathode material for solid oxide fuel cells |
Type |
A1 Journal article |
Year |
2016 |
Publication |
RSC advances |
Abbreviated Journal |
Rsc Adv |
Volume |
6 |
Issue |
6 |
Pages |
101029-101037 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Pr2−xCexCuO4 (x = 0.05; 0.1; 0.15) samples were synthesized and systematically characterized towards application as a cathode material for solid oxide fuel cells (SOFCs). High-temperature electrical conductivity, thermal expansion, and electrocatalytic activity in the oxygen reduction reaction (ORR) were examined. The electrical conductivity of Pr2−xCexCuO4 oxides demonstrates semiconducting behavior up to 900 °C. Small Ce-doping (2.5 at%) allows an increase in electrical conductivity from 100 to 130 S cm−1 in air at 500–800 °C. DFT calculations revealed that the density of states directly below the Fermi level, comprised mainly of Cu 3d and O 2p states, is significantly affected by atoms in rare earth positions, which might give an indication of a correlation between calculated electronic structures and measured conducting properties. Ce-doping in Pr2−xCexCuO4 slightly increases TEC from 11.9 × 10−6 K−1 for x = 0 to 14.2 × 10−6 K−1 for x = 0.15. Substitution of 2.5% of Pr atoms in Pr2CuO4 by Ce is effective to enhance the electrochemical performance of the material as a SOFC cathode in the ORR (ASR of Pr1.95Ce0.05CuO4 electrode applied on Ce0.9Gd0.1O1.95 electrolyte is 0.39 Ω cm2 at 750 °C in air). The peak power density achieved for the electrolyte-supported fuel cell with the Pr1.95Ce0.05CuO4 cathode is 150 mW cm−2 at 800 °C |
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 |
000387427700044 |
Publication Date |
2016-10-19 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.108 |
Times cited |
7 |
Open Access |
|
Notes |
his work was partially supported by Russian Foundation for Basic Research (grant no. 153820247), Skolkovo Institute of Science and Technology (Center of electrochemical energy), and MSUdevelopment Program up to 2020. K.L.M. is grateful to Haldor Topsøe A/S for the financial support. |
Approved |
Most recent IF: 3.108 |
Call Number |
EMAT @ emat @ c:irua:136441 |
Serial |
4296 |
Permanent link to this record |
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Author |
Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S. |
Title |
Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Nature chemistry |
Abbreviated Journal |
Nat Chem |
Volume |
8 |
Issue |
8 |
Pages |
501-508 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature. |
Address |
Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, Germany |
Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
000374534100019 |
Publication Date |
2016-04-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1755-4330 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
25.87 |
Times cited |
51 |
Open Access |
|
Notes |
S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3 |
Approved |
Most recent IF: 25.87 |
Call Number |
c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593 |
Serial |
4068 |
Permanent link to this record |
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Author |
Abakumov, A.M.; Erni, R.; Tsirlin, A.A.; Rossell, M.D.; Batuk, D.; Nénert, G.; Van Tendeloo, G. |
Title |
Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
25 |
Issue |
13 |
Pages |
2670-2683 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Perovskite-structured titanates with layered A-site ordering form remarkably complex superstructures. Using transmission electron microscopy, synchrotron X-ray and neutron powder diffraction, and ab initio structure relaxation, we present the structural solution of the incommensurately modulated Li3xNd2/3xTiO3 perovskites (x = 0.05, superspace group Pmmm(α1,1/2,0)000(1/2,β2 0)000, a = 3.831048(5) Å, b = 3.827977(4) Å, c = 7.724356(8) Å, q1 = 0.45131(8)a* + 1/2b*, q2 = 1/2a* + 0.41923(4)b*). In contrast to earlier conjectures on the nanoscale compositional phase separation in these materials, all peculiarities of the superstructure can be understood in terms of displacive modulations related to an intricate octahedral tilting pattern. It involves fragmenting the pattern of the out-of-phase tilted TiO6 octahedra around the a- and b-axes into antiphase domains, superimposed on the pattern of domains with either pronounced or suppressed in-phase tilt component around the c-axis. The octahedral tilting competes with the second order JahnTeller distortion of the TiO6 octahedra. This competition is considered as the primary driving force for the modulated structure. The A cations are suspected to play a role in this modulation affecting it mainly through the tolerance factor and the size variance. The reported crystal structure calls for a revision of the structure models proposed for the family of layered A-site ordered perovskites exhibiting a similar type of modulated structure. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000321809700015 |
Publication Date |
2013-06-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
23 |
Open Access |
|
Notes |
Countatoms |
Approved |
Most recent IF: 9.466; 2013 IF: 8.535 |
Call Number |
UA @ lucian @ c:irua:109216 |
Serial |
1292 |
Permanent link to this record |
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|
Author |
Mefford, J.T.; Rong, X.; Abakumov, A.M.; Hardin, W.G.; Dai, S.; Kolpak, A.M.; Johnston, K.P.; Stevenson, K.J. |
Title |
Water electrolysis on La1-xSrxCoO3-\delta perovskite electrocatalysts |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
7 |
Issue |
7 |
Pages |
11053 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1 – xSrxCoO3 – delta. We attempt to rationalize the high activities of La1 – xSrxCoO3 – delta through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis. |
Address |
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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 |
000372721700001 |
Publication Date |
2016-03-23 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
278 |
Open Access |
|
Notes |
Financial support for this work was provided by the R.A. Welch Foundation (grants F-1529 and F-1319). X.R. and A.M.K. acknowledge support from the Skoltech-MIT Center for Electrochemical Energy Storage. Computations were performed using computational resources from XSEDE and NERSC. S.D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. We thank D.W. Redman for help with the RHE measurements. |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ lucian @ c:irua:133242 |
Serial |
4276 |
Permanent link to this record |
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Author |
Mefford, J.T.; Kurilovich, A.A.; Saunders, J.; Hardin, W.G.; Abakumov, A.M.; Forslund, R.P.; Bonnefont, A.; Dai, S.; Johnston, K.P.; Stevenson, K.J. |
Title |
Decoupling the roles of carbon and metal oxides on the electrocatalytic reduction of oxygen on La1-xSrxCoO3-\delta perovskite composite electrodes |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
21 |
Issue |
6 |
Pages |
3327-3338 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Perovskite oxides are active room-temperature bifunctional oxygen electrocatalysts in alkaline media, capable of performing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with lower combined overpotentials relative to their precious metal counterparts. However, their semiconducting nature necessitates the use of activated carbons as conductive supports to generate applicably relevant current densities. In efforts to advance the performance and theory of oxide electrocatalysts, the chemical and physical properties of the oxide material often take precedence over contributions from the conductive additive. In this work, we find that carbon plays an important synergistic role in improving the performance of La1-xSrxCoO3- (0 x 1) electrocatalysts through the activation of O-2 and spillover of radical oxygen intermediates, HO2- and O-2(-), which is further reduced through chemical decomposition of HO2- on the perovskite surface. Through a combination of thin-film rotating disk electrochemical characterization of the hydrogen peroxide intermediate reactions (hydrogen peroxide reduction reaction (HPRR), hydrogen peroxide oxidation reaction (HPOR)) and oxygen reduction reaction (ORR), surface chemical analysis, HR-TEM, and microkinetic modeling on La1-xSrxCoO3- (0 x 1)/carbon (with nitrogen and non-nitrogen doped carbons) composite electrocatalysts, we deconvolute the mechanistic aspects and contributions to reactivity of the oxide and carbon support. |
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 |
000459584900049 |
Publication Date |
2019-01-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
; Financial support for this work was provided by the R. A. Welch Foundation (grants F-1529 and F-1319). S. D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. ; |
Approved |
Most recent IF: 4.123 |
Call Number |
UA @ admin @ c:irua:158625 |
Serial |
5244 |
Permanent link to this record |
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|
Author |
Retuerto, M.; Skiadopoulou, S.; Li, M.R.; Abakumov, A.M.; Croft, M.; Ignatov, A.; Sarkar, T.; Abbett, B.M.; Pokorný, J.; Savinov, M.; Nuzhnyy, D.; Prokleška, J.; Abeykoon, M.; Stephens, P.W.; Hodges, J.P.; Vaněk, P.; Fennie, C.J.; Rabe, K.M.; Kamba, S.; Greenblatt, M.; |
Title |
Pb2MnTeO6 double perovskite : an antipolar anti-ferromagnet |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
55 |
Issue |
55 |
Pages |
4320-4329 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Pb2MnTeO6, a new double perovskite, was synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction. Pb2MnTeO6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to similar to 120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s2 lone-pair electrons, together with a surprising off-centering of Mn2+ (d5) magnetic cations. This strong first-order phase transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below TN approximate to 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near similar to 150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb2MnTeO6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb2MnTeO6. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000375519700027 |
Publication Date |
2016-04-08 |
Series Editor |
|
Series Title |
|
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 |
9 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.857 |
Call Number |
UA @ lucian @ c:irua:134219 |
Serial |
4258 |
Permanent link to this record |
|
|
|
Author |
Batuk, M.; Tyablikov, O.A.; Tsirlin, A.A.; Kazakov, S.M.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Antipov, E.V.; Abakumov, A.M.; Hadermann, J. |
Title |
Structure and magnetic properties of a new anion-deficient perovskite Pb2Ba2BiFe4ScO13 with crystallographic shear structure |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Materials research bulletin |
Abbreviated Journal |
Mater Res Bull |
Volume |
48 |
Issue |
9 |
Pages |
3459-3465 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Pb2Ba2BiFe4ScO13, a new n = 5 member of the oxygen-deficient perovskite-based A(n)B(n)O(3n-2) homologous series, was synthesized using a solid-state method. The crystal structure of Pb2Ba2BiFe4ScO13 was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mossbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) angstrom, b = 4.0426(1) angstrom, and c=27.3435(1) angstrom. In the Pb2Ba2BiFe4ScO13 structure, quasi-two-dimensional perovskite blocks are periodically interleaved with 1/2[1 1 0] ((1) over bar 0 1)(p) crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO6 octahedra are transformed into chains of edge-sharing FeO5 distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe3+ and Sc3+. The chains of the FeO5 pyramids and (Fe,Sc)O-6 octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb2+). The remaining A-cations (Bi3+, Ba2+) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb2Ba2BiFe4ScO13 is antiferromagnetically ordered below T-N approximate to 350 K. (C) 2013 Elsevier Ltd. 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 |
New York, N.Y. |
Editor |
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Language |
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Wos |
000322354000076 |
Publication Date |
2013-05-17 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0025-5408; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.446 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.446; 2013 IF: 1.968 |
Call Number |
UA @ lucian @ c:irua:109756 |
Serial |
3282 |
Permanent link to this record |
|
|
|
Author |
Korneychik, O.E.; Batuk, M.; Abakumov, A.M.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Pokholok, K.V.; Filimonov, D.S.; Antipov, E.V. |
Title |
Pb2.85Ba2.15Fe4SnO13 : a new member of the AnBnO3n-2 anion-deficient perovskite-based homologous series |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
184 |
Issue |
12 |
Pages |
3150-3157 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Pb2.85Ba2.15Fe4SnO13, a new n=5 member of the anion-deficient perovskite based AnBnO3n−2 (A=Pb, Ba, B=Fe, Sn) homologous series, was synthesized by the solid state method. The crystal structure of Pb2.85Ba2.15Fe4SnO13 was investigated using a combination of neutron powder diffraction, electron diffraction, high angle annular dark field scanning transmission electron microscopy and Mössbauer spectroscopy. It crystallizes in the Ammm space group with unit cell parameters a=5.7990(1) Å, b=4.04293(7) Å and c=26.9561(5) Å. The Pb2.85Ba2.15Fe4SnO13 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110](1̄01)p crystallographic shear (CS) planes. The corner-sharing FeO6 octahedra at the CS planes are transformed into edge-sharing FeO5 distorted tetragonal pyramids. The octahedral positions in the perovskite blocks between the CS planes are jointly taken up by Fe and Sn, with a preference of Sn towards the position at the center of the perovskite block. The chains of FeO5 pyramids and (Fe,Sn)O6 octahedra of the perovskite blocks delimit six-sided tunnels at the CS planes occupied by double chains of Pb atoms. The compound is antiferromagnetically ordered below TN=368±15 K. |
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 |
000297662500003 |
Publication Date |
2011-09-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2011 IF: 2.159 |
Call Number |
UA @ lucian @ c:irua:94013 |
Serial |
3550 |
Permanent link to this record |
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|
|
Author |
Lomakov, M.V.; Istomin, S.Y.; Abakumov, A.M.; Van Tendeloo, G.; Antipov, E.V. |
Title |
Synthesis and characterization of oxygen-deficient oxides BaCo1-xYxO3-y' x = 0.15, 0.25 and 0.33, with the perovskite structure |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Solid state ionics |
Abbreviated Journal |
Solid State Ionics |
Volume |
179 |
Issue |
33/34 |
Pages |
1885-1889 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Oxygen-deficient complex cobalt oxides BaCo1 − xYxO3 − y, = 0.15, 0.25 and 0.33, with a cubic perovskite structure have been synthesized in air at 1100 °C using a citrate route. Cation composition of the compounds was confirmed by energy-dispersed X-ray (EDX) microanalysis while oxygen content was determined by iodometric titration. An electron diffraction (ED) study of the x = 0.25 and 0.33 compositions show the presence of a diffuse intensity, indicating possible short-range ordering of the B cations. It was found that the treatment of BaCo0.75Y0.25O2.55 in a humid atmosphere leads to the absorption of water vapour at the first stage. Oxygen permeation studies of the ceramic membranes of BaCo0.75Y0.25O2.55 and BaCo0.67Y0.33O2.55 with variable thickness showed high oxygen fluxes of 0.170.32 µmol/cm2/s at 950 °C. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000261870800009 |
Publication Date |
2008-06-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0167-2738; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.354 |
Times cited |
9 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.354; 2008 IF: 2.425 |
Call Number |
UA @ lucian @ c:irua:75905 |
Serial |
3415 |
Permanent link to this record |
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|
|
Author |
Napolsky, P.S.; Drozhzhin, O.A.; Istomin, S.Y.; Kazakov, S.M.; Antipov, E.V.; Galeeva, A.V.; Gippius, A.A.; Svensson, G.; Abakumov, A.M.; Van Tendeloo, G. |
Title |
Structure and high-temperature properties of the (Sr,Ca,Y)(Co,Mn)O3-y perovskites – perspective cathode materials for IT-SOFC |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
192 |
Issue |
|
Pages |
186-194 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Oxygen deficient perovskites Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75, were prepared by using the citrate route at 1373-1573 K for 48 h. The cubic Pm-3m perovskite structure for x=0.5 was confirmed by electron diffraction study and refined using neutron powder diffraction (NPD) data. For x=0.75, the superstructure corresponding to a=root 2 x a(per), b=2 x a(per), c=root 2 x a(per) (a(0)b(-)b(-) tilt system, space group Imma) was revealed by electron diffraction. The solid solution Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= x <= 0.6 and compound Ca0.75Y0.25Mn0.85Co0.15O2.92 were prepared in air at 1573 K for 48 h. The crystal structure of Ca0.75Y0.25Mn0.85Co0.15O2.92 was refined using NPD data (S.G. Pnma, a=5.36595(4), b=7.5091(6), c=5.2992(4) angstrom, R-p=0.057, R-wp=0.056, chi(2)=4.26). High-temperature thermal expansion properties of the prepared compounds were studied in air using both dilatometry and high-temperature X-ray powder diffraction data (HTXRPD). They expanding non-linearly at 298-1073 K due to the loss of oxygen at high temperatures. Calculated average thermal expansion coefficients (TECs) for Sr0.75Y0.25Co1-xMnxO3-y, x=0.5, 0.75 and Ca0.75Y0.25Mn0.85Co0.15O2.92(1) are 15.5, 15.1, and 13.8 ppm K-1, respectively. Anisotropy of the thermal expansion along different unit cell axes was observed for Sr0.15Ca0.6Y0.25Co0.25Mn0.75O3-y, and Ca0.75Y0.25Mn0.85Co0.15O2.92. Conductivity of Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75 increases with the temperature reaching 110 S/cm for x=0.5 and 44 S/cm for x=0.75 at 1173 K. Samples of Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= y <= 0.6 were found to be n-type conductors at room temperature with the similar temperature dependence of the conductivity and demonstrated the increase of the sigma value from similar to 1 to similar to 50 S/cm as the temperature increases from 300 to 1173 K. Their conductivity is described in terms of the small polaron charge transport with the activation energy (E-p) increasing from 340 to 430 meV with an increase of the calcium content from x=0 to x=0.6. (C) 2012 Elsevier Inc. 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 |
London |
Editor |
|
Language |
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Wos |
000307028300030 |
Publication Date |
2012-03-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2012 IF: 2.040 |
Call Number |
UA @ lucian @ c:irua:101119 |
Serial |
3279 |
Permanent link to this record |
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|
Author |
Blandy, J.N.; Abakumov, A.M.; Christensen, K.E.; Hadermann, J.; Adamson, P.; Cassidy, S.J.; Ramos, S.; Free, D.G.; Cohen, H.; Woodruff, D.N.; Thompson, A.L.; Clarke, S.J.; |
Title |
Soft chemical control of the crystal and magnetic structure of a layered mixed valent manganite oxide sulfide |
Type |
A1 Journal article |
Year |
2015 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
3 |
Issue |
3 |
Pages |
041520 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Oxidative deintercalation of copper ions from the sulfide layers of the layered mixed-valent manganite oxide sulfide Sr2MnO2Cu1.5S2 results in control of the copper-vacancy modulated superstructure and the ordered arrangement of magnetic moments carried by the manganese ions. This soft chemistry enables control of the structures and properties of these complex materials which complement mixed-valent perovskite and perovskite-related transition metal oxides. (C) 2015 Author(s). |
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 |
000353828400027 |
Publication Date |
2015-04-21 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.335; 2015 IF: NA |
Call Number |
c:irua:126021 |
Serial |
3049 |
Permanent link to this record |
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Author |
Forsh, E.A.; Abakumov, A.M.; Zaytsev, V.B.; Konstantinova, E.A.; Forsh, P.A.; Rumyantseva, M.N.; Gaskov, A.M.; Kashkarov, P.K. |
Title |
Optical and photoelectrical properties of nanocrystalline indium oxide with small grains |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Thin solid films : an international journal on the science and technology of thin and thick films |
Abbreviated Journal |
Thin Solid Films |
Volume |
595 |
Issue |
595 |
Pages |
25-31 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Optical properties, spectral dependence of photoconductivity and photoconductivity decay in nanocrystalline indium oxide In2O3 are studied. A number of nanostructured In2O3 samples with various nanocrystals size are prepared by sol-gel method and characterized using various techniques. The mean nanocrystals size varies from 7 to 8 nm to 39-41 nm depending on the preparation conditions. Structural characterization of the In2O3 samples is performed by means of transmission electron microscopy and X-ray powder diffraction. The combined analysis of ultraviolet-visible absorption spectroscopy and diffuse reflectance spectroscopy shows that nanostructuring leads to the change in optical band gap: optical band gap of the In2O3 samples (with an average nanocrystal size from 7 to 41 nm) is equal to 2.8 eV. We find out the correlation between spectral dependence of photoconductivity and optical properties of nanocrystalline In2O3: sharp increase in photoconductivity was observed to begin at 2.8 eV that is equal to the optical bandgap in the In2O3 samples, and reached its maximum at 3.2-3.3 eV. The combined analysis of the slow photoconductivity decay in air, vacuum and argon, that was accurately fitted by a stretched-exponential function, and electron paramagnetic resonance (EPR) measurements shows that the kinetics of photoconductivity decay is strongly depended on the presence of oxygen molecules in the ambient of In2O3 nanocrystals. There is the quantitative correlation between EPR and photoconductivity data. Based on the obtained data we propose the model clearing up the phenomenon of permanent photoconductivity decay in nanocrystalline In2O3. (C) 2015 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 |
|
Language |
|
Wos |
000365812400005 |
Publication Date |
2015-10-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0040-6090 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.879 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.879; 2015 IF: 1.759 |
Call Number |
UA @ lucian @ c:irua:130254 |
Serial |
4219 |
Permanent link to this record |
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|
Author |
Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J. |
Title |
Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites |
Type |
A1 Journal article |
Year |
2016 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
Volume |
10 |
Issue |
10 |
Pages |
7604-7611 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties. |
Address |
RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan |
Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
|
Language |
English |
Wos |
000381959100043 |
Publication Date |
2016-07-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.942 |
Times cited |
57 |
Open Access |
OpenAccess |
Notes |
The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 13.942 |
Call Number |
c:irua:134576 c:irua:134576 |
Serial |
4102 |
Permanent link to this record |
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Author |
Kirsanova, M.A.; Olenev, A.V.; Abakumov, A.M.; Bykov, M.A.; Shevelkov, A.V. |
Title |
Extension of the clathrate family : the type X clathrate Ge79P29S18Te6 |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
Volume |
50 |
Issue |
10 |
Pages |
2371-2374 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow). |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000288036300033 |
Publication Date |
2011-01-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1433-7851; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
11.994 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 11.994; 2011 IF: 13.455 |
Call Number |
UA @ lucian @ c:irua:88793 |
Serial |
1158 |
Permanent link to this record |
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Author |
Kirsanova, M.A.; Reshetova, L.N.; Olenev, A.V.; Abakumov, A.M.; Shevelkov, A.V. |
Title |
Semiclathrates of the GePTe system : synthesis and crystal structures |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Chemistry: a European journal |
Abbreviated Journal |
Chem-Eur J |
Volume |
17 |
Issue |
20 |
Pages |
5719-5726 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Novel compounds [Ge46−xPx]Tey (13.9≤x≤15.6, 5.92≤y≤7.75) with clathrate-like structures have been prepared and structurally characterized. They crystallize in the space group Fmequation image with the unit cell parameter changing from 20.544(2) to 20.698(2) Å (Z=8) on going from x=13.9 to x=15.6. Their crystal structure is composed of a covalently bonded Ge[BOND]P framework that hosts tellurium atoms in the guest positions and can be viewed as a peculiar variant of the type I clathrate superstructure. In contrast to the conventional type I clathrates, [Ge46−xPx]Tey contain tricoordinated (3b) atoms and no vacancies in the framework positions. As a consequence of the transformation of the framework, the majority of the guest tellurium atoms form a single covalent bond with the host framework and thus the title compounds are the first representative of semiclathrates with covalent bonding. A comparison is made with silicon clathrates and the evolution of the crystal structure upon changing the tellurium content is discussed. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
|
Wos |
000290216000028 |
Publication Date |
2011-04-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-6539; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.317 |
Times cited |
17 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.317; 2011 IF: 5.925 |
Call Number |
UA @ lucian @ c:irua:89773 |
Serial |
2981 |
Permanent link to this record |
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|
|
Author |
Abakumov, A.M.; Batuk, M.; Tsirlin, A.A.; Tyablikov, O.A.; Sheptyakov, D.V.; Filimonov, D.S.; Pokholok, K.V.; Zhidal, V.S.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; |
Title |
Structural and magnetic phase transitions in the AnBnO3n-2 anion-deficient perovskites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
52 |
Issue |
14 |
Pages |
7834-7843 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Novel anion-deficient perovskite-based ferrites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 were synthesized by solid-state reaction in air. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 belong to the perovskite-based AnBnO3n2 homologous series with n = 5 and 6, respectively, with a unit cell related to the perovskite subcell ap as ap√2 × ap × nap√2. Their structures are derived from the perovskite one by slicing it with 1/2[110]p(1̅01)p crystallographic shear (CS) planes. The CS operation results in (1̅01)p-shaped perovskite blocks with a thickness of (n 2) FeO6 octahedra connected to each other through double chains of edge-sharing FeO5 distorted tetragonal pyramids which can adopt two distinct mirror-related configurations. Ordering of chains with a different configuration provides an extra level of structure complexity. Above T ≈ 750 K for Pb2Ba2BiFe5O13 and T ≈ 400 K for Pb1.5Ba2.5Bi2Fe6O16 the chains have a disordered arrangement. On cooling, a second-order structural phase transition to the ordered state occurs in both compounds. Symmetry changes upon phase transition are analyzed using a combination of superspace crystallography and group theory approach. Correlations between the chain ordering pattern and octahedral tilting in the perovskite blocks are discussed. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 undergo a transition into an antiferromagnetically (AFM) ordered state, which is characterized by a G-type AFM ordering of the Fe magnetic moments within the perovskite blocks. The AFM perovskite blocks are stacked along the CS planes producing alternating FM and AFM-aligned FeFe pairs. In spite of the apparent frustration of the magnetic coupling between the perovskite blocks, all n = 4, 5, 6 AnFenO3n2 (A = Pb, Bi, Ba) feature robust antiferromagnetism with similar Néel temperatures of 623632 K. |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000322087100006 |
Publication Date |
2013-02-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
10 |
Open Access |
|
Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
Call Number |
UA @ lucian @ c:irua:109213 |
Serial |
3196 |
Permanent link to this record |
|
|
|
Author |
Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. |
Title |
Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
26 |
Issue |
10 |
Pages |
3306-3315 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000336637000036 |
Publication Date |
2014-05-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
35 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
Call Number |
UA @ lucian @ c:irua:117766 |
Serial |
2232 |
Permanent link to this record |
|
|
|
Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Sheptyakov, D.V.; Frontzek, M.; Hadermann, J.; Abakumov, A.M. |
Title |
Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
27 |
Issue |
27 |
Pages |
2946-2956 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000353865800028 |
Publication Date |
2015-03-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
Call Number |
c:irua:126060 |
Serial |
1807 |
Permanent link to this record |
|
|
|
Author |
Chizhov, A.; Vasiliev, R.; Rumyantseva, M.; Krylov, I.; Drozdov, K.; Batuk, M.; Hadermann, J.; Abakumov, A.; Gaskov, A. |
Title |
Light-activated sub-ppm NO2 detection by hybrid ZnO/QD nanomaterials vs. charge localization in core-shell QD |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Frontiers in materials |
Abbreviated Journal |
|
Volume |
6 |
Issue |
6 |
Pages |
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
New hybrid materials-photosensitized nanocomposites containing nanocrystal heterostructures with spatial charge separation, show high response for practically important sub-ppm level NO2 detection at room temperature. Nanocomposites ZnO/CdSe, ZnO/(CdS@CdSe), and ZnO/(ZnSe@CdS) were obtained by the immobilization of nanocrystals-colloidal quantum dots (QDs), on the matrix of nanocrystalline ZnO. The formation of crystalline core-shell structure of QDs was confirmed by HAADF-STEM coupled with EELS mapping. Optical properties of photosensitizers have been investigated by optical absorption and luminescence spectroscopy combined with spectral dependences of photoconductivity, which proved different charge localization regimes. Photoelectrical and gas sensor properties of nanocomposites have been studied at room temperature under green light (max = 535 nm) illumination in the presence of 0.12-2 ppm NO2 in air. It has been demonstrated that sensitization with type II heterostructure ZnSe@CdS with staggered gap provides the rapid growth of effective photoresponse with the increase in the NO2 concentration in air and the highest sensor sensitivity toward NO2. We believe that the use of core-shell QDs with spatial charge separation opens new possibilities in the development of light-activated gas sensors working without thermal heating. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000487641600002 |
Publication Date |
2019-09-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2296-8016 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
Notes |
; This work was financially supported by RFBR grant No. 1653-76001 (RFBR – ERA.Net FONSENS 096) and in part by a grant from the St. Petersburg State University – Event 3-2018 (id: 26520408). AC acknowledges support from the RFBR grant No. 18-33-01004. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:163776 |
Serial |
5390 |
Permanent link to this record |
|
|
|
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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000414151800068 |
Publication Date |
2017-08-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
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 |
|
|
|
Author |
Vorobyeva, N.; Rumyantseva, M.; Filatova, D.; Konstantinova, E.; Grishina, D.; Abakumov, A.; Turner, S.; Gaskov, A. |
Title |
Nanocrystalline ZnO(Ga) : paramagnetic centers, surface acidity and gas sensor properties |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
Volume |
182 |
Issue |
|
Pages |
555-564 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Nanocrystalline ZnO and ZnO(Ga) samples with different gallium content were prepared by wet-chemical method. Introduction of gallium leads to the increase of amount of weak acid sites such as surface hydroxyl groups. Gas sensing properties toward 0.22 ppm H2S and NO2 were studied at 100450 °C by DC conductance measurements. The optimal temperature for gas sensing experiments was determined. Sensor signal toward H2S decreases with increase of Ga concentration. The dependence of ZnO(Ga) sensor signal to NO2 on the gallium content has non-monotonous character, which correlates with the change of conductivity of the samples in air and concentration of paramagnetic donor states. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
Language |
|
Wos |
000319488800075 |
Publication Date |
2013-03-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0925-4005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.401 |
Times cited |
42 |
Open Access |
|
Notes |
Hercules; FWO |
Approved |
Most recent IF: 5.401; 2013 IF: 3.840 |
Call Number |
UA @ lucian @ c:irua:107346 |
Serial |
2250 |
Permanent link to this record |
|
|
|
Author |
Ilin, A.; Martyshov, M.; Forsh, E.; Forsh, P.; Rumyantseva, M.; Abakumov, A.; Gaskov, A.; Kashkarov, P. |
Title |
UV effect on NO2 sensing properties of nanocrystalline In2O3 |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
Volume |
231 |
Issue |
231 |
Pages |
491-496 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Nanocrystalline indium oxide films with extremely small grains in range of 7-40 nm are prepared by sol-gel method. The influence of grain size on the sensitivity of indium oxide to nitrogen dioxide in low concentration at room temperature is investigated under the UV illumination and without illumination. The sensitivity increases with the decrease of grain sizes when In2O3 is illuminated while in the dark In2O3 with intermediate grain size exhibits the highest response. An explanation of the different behavior of the In2O3 with different grain size sensitivity to NO2 under illumination and in the dark is proposed. We demonstrate that pulsed illumination may be used for NO2 detection at room temperature that significantly reduces the power consumption of sensor. (C) 2016 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
Language |
|
Wos |
000374330900055 |
Publication Date |
2016-03-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.401 |
Times cited |
27 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.401 |
Call Number |
UA @ lucian @ c:irua:133630 |
Serial |
4273 |
Permanent link to this record |
|
|
|
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 |
|
Issue |
|
Pages |
2884-2890 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000453805100005 |
Publication Date |
2018-11-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2380-8195 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access: Available from 06.11.2019
|
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 |
|
|
|
Author |
Reynaud, M.; Rousse, G.; Abakumov, A.M.; Sougrati, M.T.; Van Tendeloo, G.; Chotard, J.-N.; Tarascon, J.-M. |
Title |
Design of new electrode materials for Li-ion and Na-ion batteries from the bloedite mineral Na2Mg(SO4)2\cdot4H2O |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
Volume |
2 |
Issue |
8 |
Pages |
2671-2680 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Mineralogy offers a large database to search for Li- or Na-based compounds having suitable structural features for acting as electrode materials, LiFePO4 being one example. Here we further explore this avenue and report on the electrochemical properties of the bloedite type compounds Na2M(SO4)(2)center dot 4H(2)O (M = Mg, Fe, Co, Ni, Zn) and their dehydrated phases Na2M(SO4)(2) (M = Fe, Co), whose structures have been solved via complementary synchrotron X-ray diffraction, neutron powder diffraction and transmission electron microscopy. Among these compounds, the hydrated and anhydrous iron-based phases show electrochemical activity with the reversible release/uptake of 1 Na+ or 1 Li+ at high voltages of similar to 3.3 V vs. Na+/Na-0 and similar to 3.6 V vs. Li+/Li-0, respectively. Although the reversible capacities remain lower than 100 mA h g(-1), we hope this work will stress further the importance of mineralogy as a source of inspiration for designing eco-efficient electrode materials. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000331247500031 |
Publication Date |
2013-11-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2050-7488;2050-7496; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.867 |
Times cited |
56 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.867; 2014 IF: 7.443 |
Call Number |
UA @ lucian @ c:irua:115807 |
Serial |
659 |
Permanent link to this record |
|
|
|
Author |
Alexander, C.T.; Abakumov, A.M.; Forslund, R.P.; Johnston, K.P.; Stevenson, K.J. |
Title |
Role of the carbon support on the oxygen reduction and evolution activities in LaNiO3 composite electrodes in alkaline solution |
Type |
A1 Journal article |
Year |
2018 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
|
Volume |
1 |
Issue |
4 |
Pages |
1549-1558 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Metal-air batteries and fuel cells show a great deal of promise in advancing low-cost, high-energy-density charge storage solutions for sustainable energy applications. To improve the activities and stabilities of electrocatalysts for the critical oxygen reduction and evolution reactions (ORR and OER, respectively), a greater understanding is needed of the catalyst/carbon interactions and carbon stability. Herein, we report how LaNiO3 (LNO) supported on nitrogen-doped carbon nanotubes (N-CNT) made from a high-yield synthesis lowers the overpotential for both the OER and ORR markedly to enable a low bifunctional window of 0.81 V at only a 51 mu g cm(-2) mass loading. Furthermore, the addition of LNO to the N-CNTs improves the galvanostatic stability for the OER by almost 2 orders of magnitude. The nanoscale geometries of the perovskites and the CNTs enhance the number of metal-support and charge transfer interactions and thus the activity. We use rotating ring disk electrodes (RRDEs) combined with Tafel slope analysis and ICP-OES to quantitatively separate current contributions from the OER, carbon oxidation, and even anodic iron leaching from carbon nanotubes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000458705400020 |
Publication Date |
2018-03-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2574-0962 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:157642 |
Serial |
8487 |
Permanent link to this record |
|
|
|
Author |
McCalla, E.; Prakash, A.S.; Berg, E.; Saubanere, M.; Abakumov, A.M.; Foix, D.; Klobes, B.; Sougrati, M.T.; Rousse, G.; Lepoivre, F.; Mariyappan, S.; Doublet, M.L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Hermann, R.P.; Tarascon, J.M.; |
Title |
Reversible Li-intercalation through oxygen reactivity in Li-rich Li-Fe-Te oxide materials |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of the electrochemical society |
Abbreviated Journal |
J Electrochem Soc |
Volume |
162 |
Issue |
162 |
Pages |
A1341-A1351 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Lithium-rich oxides are a promising class of positive electrode materials for next generation lithium-ion batteries, and oxygen plays a prominent role during electrochemical cycling either by forming peroxo-like species and/or by irreversibly forming oxygen gas during first charge. Here, we present Li-Fe-Te-O materials which show a tremendous amount of oxygen gas release. This oxygen release accounts for nearly all the capacity during the first charge and results in vacancies as seen by transmission electron microscopy. There is no oxidation of either metal during charge but significant changes in their environments. These changes are particularly extreme for tellurium. XRD and neutron powder diffraction both show limited Changes during cycling and no appreciable change in lattice parameters. A density functional theory study of this material is performed and demonstrates that the holes created on some of the oxygen atoms upon oxidation are partially stabilized through the formation of shorter O-O bonds, i.e. (O-2)(n-) species which on further delithiation show a spontaneous O-2 de-coordination from the cationic network and migration to the now empty lithium layer. The rate limiting step during charge is undoubtedly the diffusion of oxygen either out along the lithium layer or via columns of oxygen atoms. (C) 2015 The Electrochemical Society. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000355643700030 |
Publication Date |
2015-04-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0013-4651;1945-7111; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.259 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.259; 2015 IF: 3.266 |
Call Number |
c:irua:126445 |
Serial |
2903 |
Permanent link to this record |
|
|
|
Author |
Pearce, P.E.; Perez, A.J.; Rousse, G.; Saubanère, M.; Batuk, D.; Foix, D.; McCalla, E.; Abakumov, A.M.; Van Tendeloo, G.; Doublet, M.-L.; Tarascon, J.-M. |
Title |
Evidence for anionic redox activity in a tridimensional-ordered Li-rich positive electrode β-Li2IrO3 |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
Volume |
16 |
Issue |
5 |
Pages |
580-586 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Lithium-ion battery cathode materials have relied on cationic redox reactions until the recent discovery of anionic redox activity in Li-rich layered compounds which enables capacities as high as 300 mAh g(-1). In the quest for new high-capacity electrodes with anionic redox, a still unanswered question was remaining regarding the importance of the structural dimensionality. The present manuscript provides an answer. We herein report on a beta-Li2IrO3 phase which, in spite of having the Ir arranged in a tridimensional (3D) framework instead of the typical two-dimensional (2D) layers seen in other Li-rich oxides, can reversibly exchange 2.5 e(-) per Ir, the highest value ever reported for any insertion reaction involving d-metals. We show that such a large activity results from joint reversible cationic (Mn+) and anionic (O-2)(n-) redox processes, the latter being visualized via complementary transmission electron microscopy and neutron diffraction experiments, and confirmed by density functional theory calculations. Moreover, beta-Li2IrO3 presents a good cycling behaviour while showing neither cationic migration nor shearing of atomic layers as seen in 2D-layered Li-rich materials. Remarkably, the anionic redox process occurs jointly with the oxidation of Ir4+ at potentials as low as 3.4 V versus Li+/Li-0, as equivalently observed in the layered alpha-Li2IrO3 polymorph. Theoretical calculations elucidate the electrochemical similarities and differences of the 3D versus 2D polymorphs in terms of structural, electronic and mechanical descriptors. Our findings free the structural dimensionality constraint and broaden the possibilities in designing high-energy-density electrodes for the next generation of Li-ion batteries. |
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Wos |
000400004200018 |
Publication Date |
2017-02-27 |
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1476-1122 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
39.737 |
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Open Access |
Not_Open_Access |
Notes |
The authors thank Q. Jacquet for fruitful discussions and V. Pomjakushin for his valuable help in neutron diffraction experiments. This work is based on experiments performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institute, Villigen, Switzerland. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the US Department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. E.M. acknowledges financial support from the Fonds de Recherche du Quebec-Nature et Technologies. |
Approved |
Most recent IF: 39.737 |
Call Number |
EMAT @ emat @c:irua:147502 |
Serial |
4773 |
Permanent link to this record |