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Author |
Piorra, A.; Hrkac, V.; Wolff, N.; Zamponi, C.; Duppel, V.; Hadermann, J.; Kienle, L.; Quandt, E. |
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Title |
(Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 thin films prepared by PLD : relaxor properties and complex microstructure |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
125 |
Issue |
24 |
Pages |
244103 |
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Keywords  |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Ferroelectric lead-free thin films of the composition (Ba0.85Ca0.15)(Ti0.9Zr0.1)O-3 (BCZT) were deposited by pulsed laser deposition on Pt/TiO2/SiO2/Si substrates using a ceramic BCZT target prepared by a conventional solid state reaction. The target material itself shows a piezoelectric coefficient of d(33)=640pm/V. The (111) textured thin films possess a thickness of up to 1.1 mu m and exhibit a clamped piezoelectric response f of up to 190pm/V, a dielectric coefficient of (r)=2000 at room temperature, and a pronounced relaxor behavior. As indicated by transmission electron microscopy, the thin films are composed of longitudinal micrometersized columns with similar to 100nm lateral dimension that are separated at twin- and antiphase boundaries. The superposition phenomena according to this columnar growth were simulated based on suitable supercells. The major structural component is described as a tetragonal distorted variant of the perovskite parent type; however, frequently coherently intergrown nanodomains were observed indicating a much more complex structure that is characterized by a 7-layer modulation along the growth direction of the films. |
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Wos |
000474439600002 |
Publication Date |
2019-06-25 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
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Open Access |
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Notes |
; The authors want to thank Dr. Martina Luysberg and Dr. Lothar Houben from the Ernst Ruska Centre in Julich for discussion and CS-corrected microscopy. Funding of this work via the DFG (No. CRC1261) “Magnetoelectric Sensors: From Composite Materials to Biomagnetic Diagnostics” and the PAK902 is gratefully acknowledged. ; |
Approved |
Most recent IF: 2.068 |
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Call Number |
UA @ admin @ c:irua:161310 |
Serial |
5399 |
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Author |
Kirsanova, M.A.; De Sloovere, D.; Karakulina, O.M.; Hadermann, J.; Van Bael, M.K.; Hardy, A.; Abakumov, A.M. |
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Title |
Toward unlocking the Mn3+/Mn2+ redox pair in alluaudite-type Na2+2zMn2-z(SO4)3-x(SeO4)x cathodes for sodium-ion batteries |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
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| |
Volume |
277 |
Issue |
277 |
Pages |
804-810 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In polyanion cathodes, the inductive effect alters the potential of a M(n+1)+/Mn+ redox couple (M – transition metal) according to the electronegativity of the X cation in the polyanion groups (XO4m+). To manipulate the operating potential, we synthesized a series of mixed sulfate-selenate alluaudites, with structure formulas Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) and Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57). Their crystal structure was determined from powder X-ray diffraction data, revealing that the Mn-based alluaudites form solid solutions with the same crystal structure for x = 0.75; 1.125 and 1.5. Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57) is isostructural to the Mn-based alluaudites. Although the Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) compound with the highest selenium content demonstrates a reversible discharge capacity of 60 mAh g(-1), only a small part of this electrochemical activity can be ascribed to the Mn3+/Mn2+ redox couple. The redox potential of the Mn3+/Mn2+ pair in Na2+2zMn2-z(SO4)(3-)x(SeO4)(x) decreases with increasing values of x, in agreement with the lower electronegativity of Se compared to that of S. |
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Wos |
000481726300103 |
Publication Date |
2019-07-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.299 |
Times cited |
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Open Access |
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Notes |
; The authors thank the Russian Foundation for Basic Research for financial support (grant 17-03-00370), in addition to Research Foundation-Flanders (project No G040116). ; |
Approved |
Most recent IF: 2.299 |
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Call Number |
UA @ admin @ c:irua:162852 |
Serial |
5401 |
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Author |
Fedotov, S.S.; Aksyonov, D.A.; Samarin, A.S.; Karakulina, O.M.; Hadermann, J.; Stevenson, K.J.; Khasanova, N.R.; Abakumov, A.M.; Antipov, E., V |
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Title |
Tuning the crystal structure of A2CoPO4F(A=Li,Na) fluoride-phosphates : a new layered polymorph of LiNaCoPO4F |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
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| |
Volume |
2019 |
Issue |
2019 |
Pages |
4365-4372 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Co-containing fluoride-phosphates are of interest in sense of delivering high electrode potentials and attractive specific energy values as positive electrode materials for rechargeable batteries. In this paper we report on a new Co-based fluoride-phosphate, LiNaCoPO4F, with a layered structure (2D), which was Rietveld-refined based on X-ray powder diffraction data [P2(1)/c, a = 6.83881(4) angstrom, b = 11.23323(5) angstrom, c = 5.07654(2) angstrom, beta = 90.3517(5) degrees, V = 389.982(3) angstrom(3)] and validated by electron diffraction and high-resolution scanning transmission electron microscopy. The differential scanning calorimetry measurements revealed that 2D-LiNaCoPO4F forms in a narrow temperature range of 520-530 degrees C and irreversibly converts to the known 3D-LiNaCoPO4F modification (Pnma) above 530 degrees C. The non-carbon-coated 2D-LiNaCoPO4F shows reversible electrochemical activity in Li-ion cell in the potential range of 3.0-4.9 V vs. Li/Li+ with an average potential of approximate to 4.5 V and in Na-ion cell in the range of 3.0-4.5 V vs. Na/Na+ exhibiting a plateau profile centered around 4.2 V, in agreement with the calculated potentials by density functional theory. The energy barriers for both Li+ and Na+ migration in 2D-LiNaCoPO4F amount to 0.15 eV along the [001] direction rendering 2D-LiNaCoPO4F as a viable electrode material for high-power Li- and Na-ion rechargeable batteries. The discovery and stabilization of the 2D-LiNaCoPO4F polymorph indicates that temperature influence on the synthesis of A(2)MPO(4)F fluoride-phosphates needs more careful examination with perspective to unveil new structures. |
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Wos |
000484135500001 |
Publication Date |
2019-08-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-1948 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.444 |
Times cited |
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Open Access |
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Notes |
; This work is supported by the Russian Science Foundation (grant 17-73-30006). The authors greatly thank Dr. D. Rupasov for TG-DSC experiments, B. D. Shmykov and A. I. Manoilov for assistance with sample preparation, the Skoltech Center for Energy Science and Technology and the Moscow State University Program of Development up to 2020. J. Hadermann and O. M. Karakulina acknowledge support from the FWO under grant G040116N. ; |
Approved |
Most recent IF: 2.444 |
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Call Number |
UA @ admin @ c:irua:162857 |
Serial |
5403 |
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Author |
Jin, L.; Batuk, M.; Kirschner, F.K.K.; Lang, F.; Blundell, S.J.; Hadermann, J.; Hayward, M.A. |
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Title |
Exsolution of SrO during the Topochemical Conversion of LaSr3CoRuO8to the Oxyhydride LaSr3CoRuO4H4 |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
58 |
Issue |
21 |
Pages |
14863-14870 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Reaction of the n = 1 Ruddlesden-Popper oxide LaSr3CoRuO8 with CaH2 yields the oxyhydride phase LaSr3CoRuO4H4 via topochemical anion-exchange. Close inspection of X-ray and neutron powder diffraction data in combination with HAADF-STEM images reveals that nanoparticles of SrO are exsolved from the system during the reaction, with the change in cation stoichiometry accommodated by the inclusion of n > 1 (Co/Ru)nOn+1H2n ‘perovskite’ layers into the Ruddlesden-Popper stacking sequence. This novel pseudo-topochemical process offers a new route for the formation of n > 1 Ruddlesden-Popper structured materials. Magnetization data are consistent with a LaSr3Co1+Ru2+O4H4 (Co1+, d8, S = 1; Ru2+, d6, S = 0) oxidation/spin state combination. Neutron diffraction and μ+SR data show no evidence for long-range magnetic order down to 2 K, suggesting the diamagnetic Ru2+ centers impede the Co-Co magnetic exchange interactions. |
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Wos |
000494894400062 |
Publication Date |
2019-11-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
1 |
Open Access |
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Notes |
We thank P. Manuel for assistance collecting the neutron powder diffraction data. We thank The Leverhulme Trust grant award RPG-2014-366 “Topochemical reduction of 4d and 5d transition metal oxides” for supporting this work. 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). Investigation by TEM was supported through the FWO grant G035619N. |
Approved |
Most recent IF: 4.857 |
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Call Number |
EMAT @ emat @c:irua:164625 |
Serial |
5434 |
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Author |
Morozov, V.A.; Posokhova, S.M.; Deyneko, D., V; Savina, A.A.; Morozov, A., V; Tyablikov, O.A.; Redkin, B.S.; Spassky, D.A.; Hadermann, J.; Lazoryak, B., I |
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Title |
Influence of annealing conditions on the structure and luminescence properties of KGd1-xEux(MoO4)2(0\leq x\leq1) |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
CrystEngComm |
Abbreviated Journal |
Crystengcomm |
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Volume |
21 |
Issue |
42 |
Pages |
6460-6471 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This study describes the influence of annealing temperature on the structure and luminescence properties of KGd1-xEux(MoO4)(2) (0 <= x <= 1). Compounds with the general formula (A ', A '')(n)[(W, Mo)O-4](m) are investigated as luminescent materials for photonic applications such as phosphor-converted LEDs (light-emitting diodes). Herein, the KGd0.8Eu0.2(MoO4)(2) light-rose crystal was grown by the Czochralski technique. Moreover, three polymorphs of KGd1-xEux(MoO4)(2) were present in the 923-1223 K range of annealing temperatures under ambient pressure: a triclinic alpha-phase, a disproportionately modulated monoclinic beta-phase and an orthorhombic gamma-phase with a KY(MoO4)(2)-type structure. The different behaviors of KGd(MoO4)(2) and KEu(MoO4)(2) were revealed by DSC studies. The number and the character of phase transitions for KGd1-xEux(MoO4)(2) depended on the elemental composition. The formation of a continuous range of solid solutions with the triclinic alpha-KEu(MoO4)(2)-type structure and ordering of K+ and Eu3+/Gd3+ cations were observed only for alpha-KGd1-xEux(MoO4)(2) (0 <= x <= 1) prepared at 923 K. The structures of gamma-KGd1-xEux(MoO4)(2) (x = 0 and 0.2) were studied using electron diffraction and refined using the powder X-ray diffraction data. The luminescence properties of KGd1-xEux(MoO4)(2) prepared at different annealing temperatures were studied and related to their different structures. The maxima of the D-5(0) -> F-7(2) integral emission intensities were found under excitation at lambda(ex) = 300 nm and lambda(ex) = 395 nm for triclinic scheelite-type alpha-KGd0.6Eu0.4(MoO4)(2) and monoclinic scheelite-type beta-KGd0.4Eu0.6(MoO4)(2) prepared at 1173 K, respectively. The latter shows the brightest red light emission among the KGd1-xEux(MoO4)(2) phosphors. The maximum and integral emission intensity of beta-KGd0.4Eu0.6(MoO4)(2) in the D-5(0) -> F-7(2) transition region is similar to 20% higher than that of the commercially used red phosphor Gd2O2S:Eu3+. Thus, beta-KGd0.4Eu0.6(MoO4)(2) is very attractive for application as a near-UV convertible red-emitting phosphor for LEDs. |
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Wos |
000493072200015 |
Publication Date |
2019-09-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1466-8033 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.474 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.474 |
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Call Number |
UA @ admin @ c:irua:164603 |
Serial |
6304 |
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Author |
Saveleva, V.A.; Wang, L.; Kasian, O.; Batuk, M.; Hadermann, J.; Gallet, J.-j.; Bournel, F.; Alonso-Vante, N.; Ozouf, G.; Beauger, C.; Mayrhofer, K.J.J.; Cherevko, S.; Gago, A.S.; Friedrich, K.A.; Zafeiratos, S.; Savinova, E.R. |
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Title |
Insight into the Mechanisms of High Activity and Stability of Iridium Supported on Antimony-Doped Tin Oxide Aerogel for Anodes of Proton Exchange Membrane Water Electrolyzers |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Acs Catalysis |
Abbreviated Journal |
Acs Catal |
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Volume |
10 |
Issue |
4 |
Pages |
2508-2516 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The use of high amounts of iridium in industrial proton exchange membrane water electrolysers (PEMWE) could hinder their widespread use for the decarbonisation of society with hydrogen. Non-thermally oxidised Ir nanoparticles supported on antimony-doped tin oxide (SnO2:Sb, ATO) aerogel allow decreasing the use of the precious metal by more than 70 %, while enhancing the electro-catalytic activity and stability. To date the origin of these benefits remains unknown. Here we present clear evidence on the mechanisms that lead to the enhancement of the electrochemical properties of the catalyst. Operando near ambient pressure X-ray photoelectron spectroscopy on membrane electrode assemblies reveals a low degree of Ir oxidation, attributed to the oxygen spill-over from Ir to SnO2:Sb. Furthermore, the formation of highly unstable Ir(III) species is mitigated, while the decrease of Ir dissolution in Ir/SnO2:Sb is confirmed by inductively coupled plasma mass spectrometry (ICP-MS). The mechanisms that lead to the high activity and stability of Ir catalyst supported on SnO2:Sb aerogel for PEMWE are thus unveiled. |
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Corporate Author |
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Language |
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Wos |
000516887400011 |
Publication Date |
2020-02-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2155-5435 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.9 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
The research leading to these results has received funding from the European Union’s Seventh Framework Program (FP7/2007-2013) for Fuel Cell and Hydrogen Joint Technology (FCH JU) Initiative under Grant No. 621237 (INSIDE). In addition, A.S.G. and C.B. thank the European Union’s Horizon 2020 research and innovation programme for funding the project PRETZEL under grant agreement No 779478 and it is supported by FCH JU. Solvay is acknowledged for providing Aquivion membrane and ionomer. |
Approved |
Most recent IF: 12.9; 2020 IF: 10.614 |
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Call Number |
EMAT @ emat @c:irua:167147 |
Serial |
6341 |
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Author |
Rumyantseva, M.N.; Vladimirova, S.A.; Platonov, V.B.; Chizhov, A.S.; Batuk, M.; Hadermann, J.; Khmelevsky, N.O.; Gaskov, A.M. |
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Title |
Sub-ppm H2S sensing by tubular ZnO-Co3O4 nanofibers |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
307 |
Issue |
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Pages |
127624 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Tubular ZnO – Co3O4 nanofibers were co-electrospun from polymer solution containing zinc and cobalt acetates. Phase composition, cobalt electronic state and element distribution in the fibers were investigated by XRD, SEM, HRTEM, HAADF-STEM with EDX mapping, and XPS. Bare ZnO has high selective sensitivity to NO and NO2, while ZnO-Co3O4 composites demonstrate selective sensitivity to H2S in dry and humid air. This effect is discussed in terms of transformation of cobalt oxides into cobalt sulfides and change in the acidity of ZnO oxide surface upon cobalt doping. Reduction in response and recovery time is attributed to the formation of a tubular structure facilitating gas transport through the sensitive layer. |
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Place of Publication |
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Wos |
000508110400059 |
Publication Date |
2019-12-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
This work was supported by RFBR grants No. 18-03-00091 and No. 18-03-00580. |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @c:irua:166449 |
Serial |
6343 |
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Author |
Hendrickx, M.; Tang, Y.; Hunter, E.C.; Battle, P.D.; Cadogan, Jm.; Hadermann, J. |
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Title |
CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A = Ca, Sr, Ba): cation-ordered, inhomogeneous, ferrimagnetic perovskites |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Solid State Chemistry |
Abbreviated Journal |
J Solid State Chem |
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Volume |
285 |
Issue |
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Pages |
121226 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Polycrystalline samples of CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A=Ca, Sr, Ba) have been prepared in solid-state reactions and studied by a combination of transmission electron microscopy, magnetometry, X-ray diffraction, neutron diffraction and Mössbauer spectroscopy. Diffraction and TEM showed that each shows 1:1 B-site ordering in which Co2+/Ni2+ and Sb5+ tend to occupy two distinct crystallographic sites while Fe3+ is distributed over both sites. While X-ray and neutron diffraction agreed that all four compositions are monophasic with space group P21/n, TEM revealed different levels of compositional inhomogeneity at the subcrystal scale, which, in the case of BaLa2FeNiSbO9, leads to the occurrence of both a P21/n and an I2/m phase. Magnetometry and neutron diffraction show that these perovskites are ferrimagnets with a G-type magnetic structure. Their relatively low magnetisation can be attributed to their inhomogeneity. This work demonstrates the importance of studying the microstructure of complex compositions. |
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Place of Publication |
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Language |
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Wos |
000521107900017 |
Publication Date |
2020-01-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.3 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
PDB, ECH, and JH acknowledge support from EPSRC under grant EP/M0189954/1. We would also like to thank E. Suard at ILL and I. Da Silva at ISIS for the experimental assistance they provided. |
Approved |
Most recent IF: 3.3; 2020 IF: 2.299 |
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Call Number |
EMAT @ emat @c:irua:167137 |
Serial |
6345 |
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Author |
Chin, C.–M.; Battle, P.D.; Hunter, E.C.; Avdeev, M.; Hendrickx, M.; Hadermann, J. |
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Title |
Magnetic properties of La3Ni2Sb Ta Nb1––O9; from relaxor to spin glass |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of solid state chemistry (Print) |
Abbreviated Journal |
Journal of Solid State Chemistry |
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Volume |
273 |
Issue |
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Pages |
175-185 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Neutron diffraction experiments conducted at 5 K in a magnetic field 0 < H/kOe < 50 have shown that the monoclinic perovskite La3Ni2TaO9 behaves as a relaxor ferromagnet. Compositions in the series La3Ni2SbxTayNb1–x–yO9 have been synthesized in polycrystalline form. Electron microscopy, X–ray diffraction and neutron diffraction have shown that the solid solutions are largely homogeneous and monophasic. Magnetometry and neutron diffraction have shown that the relaxor magnetisation persists in low fields when x + y = 1 but is rapidly diminished by the introduction of niobium. This change in magnetic behaviour is ascribed to the differences in the d–orbital energies of Sb5+, Nb5+ and Ta5+. |
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Wos |
000466261100026 |
Publication Date |
2019-03-02 |
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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 |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
We thank EPSRC for funding through grant EP/M0189541. CMC thanks the Croucher Foundation and the University of Oxford for the award of a graduate scholarship. |
Approved |
no |
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| |
Call Number |
EMAT @ emat @c:irua:166445 |
Serial |
6346 |
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| Permanent link to this record |
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Author |
Paulus, A.; Hendrickx, M.; Bercx, M.; Karakulina, O.M.; Kirsanova, M.A.; Lamoen, D.; Hadermann, J.; Abakumov, A.M.; Van Bael, M.K.; Hardy, A. |
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Title |
An in-depth study of Sn substitution in Li-rich/Mn-rich NMC as a cathode material for Li-ion batteries |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
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| |
Volume |
49 |
Issue |
30 |
Pages |
10486-10497 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Layered Li-rich/Mn-rich NMC (LMR-NMC) is characterized by high initial specific capacities of more than 250 mA h g(-1), lower cost due to a lower Co content and higher thermal stability than LiCoO2. However, its commercialisation is currently still hampered by significant voltage fade, which is caused by irreversible transition metal ion migration to emptied Li positionsviatetrahedral interstices upon electrochemical cycling. This structural change is strongly correlated with anionic redox chemistry of the oxygen sublattice and has a detrimental effect on electrochemical performance. In a fully charged state, up to 4.8 Vvs.Li/Li+, Mn4+ is prone to migrate to the Li layer. The replacement of Mn4+ for an isovalent cation such as Sn4+ which does not tend to adopt tetrahedral coordination and shows a higher metal-oxygen bond strength is considered to be a viable strategy to stabilize the layered structure upon extended electrochemical cycling, hereby decreasing voltage fade. The influence of Sn4+ on the voltage fade in partially charged LMR-NMC is not yet reported in the literature, and therefore, we have investigated the structure and the corresponding electrochemical properties of LMR-NMC with different Sn concentrations. We determined the substitution limit of Sn4+ in Li1.2Ni0.13Co0.13Mn0.54-xSnxO2 by powder X-ray diffraction and transmission electron microscopy to be x approximate to 0.045. The limited solubility of Sn is subsequently confirmed by density functional theory calculations. Voltage fade for x= 0 andx= 0.027 has been comparatively assessed within the 3.00 V-4.55 V (vs.Li/Li+) potential window, from which it is concluded that replacing Mn4+ by Sn4+ cannot be considered as a viable strategy to inhibit voltage fade within this window, at least with the given restricted doping level. |
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Wos |
000555330900018 |
Publication Date |
2020-07-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0300-9246; 1477-9226; 1472-7773 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
; The authors acknowledge Research Foundation Flanders (FWO) project number G040116N for funding. The authors are grateful to Dr Ken Elen and Greet Cuyvers (imo-imomec, UHasselt and imec) for respectively preliminary PXRD measurements and performing ICP-AES on the monometal precursors. Dr Dmitry Rupasov (Skolkovo Institute of Science and Technology) is acknowledged for performing TGA measurements on the metal sulfate precursors. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 4; 2020 IF: 4.029 |
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| |
Call Number |
UA @ admin @ c:irua:171149 |
Serial |
6450 |
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| Permanent link to this record |
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Author |
Vishwakarma, M.; Agrawal, K.; Hadermann, J.; Mehta, B.R. |
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Title |
Investigating the effect of sulphurization on volatility of compositions in Cu-poor and Sn-rich CZTS thin films |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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| |
Volume |
507 |
Issue |
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Pages |
145043 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In the present work, the Cu-poor and Sn-rich CZTS thin films were prepared in order to study the volatility of Sn with respect to other components. Thin film compositions were kept intentionally Sn-rich to understand the behaviour of loss and segregation of Sn during sulphurization. The homogeneous composition distribution in precursor thin films turns heterogeneous with a change in morphology after sulphurization. The inability of identifying nanoscale secondary phases in CZTS thin film by conventional analytical techniques such as XRD and Raman, can be fulfilled by employing HAADF-STEM analysis. XPS and HAADF-STEM analyses provide the quantification of nanoscale secondary phases across the thin film and surface, respectively. The volatility of Sn was revealed in the form of segregation in the middle layer of CZTS cross-sectional lamella rather than loss to annealing atmosphere. It was observed that among the cations of CZTS, Sn segregates more than Cu, while Zn segregates least. The nanoscale spurious phases were observed to vary across different regions in the sulphurized CZTS sample. The reactive annealing lead to grain growth and formation of grain boundary features in the CZTS thin films, where annealing significantly modifies the potential difference and band bending at grain boundaries with respect to intra-grains. |
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Wos |
000520021200053 |
Publication Date |
2019-12-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
4 |
Open Access |
OpenAccess |
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Notes |
; Authors acknowledges support provided by DST, India in the forms of InSOL project. We also acknowledge Dr. Indrani Mishra for XPS measurements and DST-FIST Raman facility for Raman measurements. Manoj Vishwakarma acknowledges IIT Delhi, New Delhi, India for MHRD fellowship. Prof. B.R. Mehta acknowledges the support of the Schlumberger chair professorship. ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
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Call Number |
UA @ admin @ c:irua:168603 |
Serial |
6552 |
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| Permanent link to this record |
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Author |
Vishwakarma, M.; Varandani, D.; Hendrickx, M.; Hadermann, J.; Mehta, B.R. |
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Title |
Nanoscale photovoltage mapping in CZTSe/CuxSe heterostructure by using kelvin probe force microscopy |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Materials Research Express |
Abbreviated Journal |
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| |
Volume |
7 |
Issue |
1 |
Pages |
016418 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In the present work, kelvin probe force microscopy (KPFM) technique has been used to study the CZTSe/CuxSe bilayer interface prepared by multi-step deposition and selenization process of metal precursors. Transmission electron microscopy (TEM) confirmed the bilayer configuration of the CZTSe/CuxSe sample. Two configuration modes (surface mode and junction mode) in KPFM have been employed in order to measure the junction voltage under illumination conditions. The results show that CZTSe/CuxSe has small junction voltage of similar to 21 mV and the presence of CuxSe secondary phase in the CZTSe grain boundaries changes the workfunction of the local grain boundaries region. The negligible photovoltage difference between grain and grain boundaries in photovoltage image indicates that CuxSe phase deteriorates the higher photovoltage at grain boundaries normally observed in CZTSe based device. These results can be important for understanding the role of secondary phases in CZTSe based junction devices. |
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Wos |
000520120900001 |
Publication Date |
2019-12-27 |
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Series Editor |
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Edition |
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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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Notes |
; Authors acknowledges support provided DST in the forms of InSOL and Indo-Swiss projects. We also acknowledge Joke Hadermann EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Belgium for helping in TEM measurements. M V Manoj Vishwakarma acknowledges IIT Delhi for MHRD fellowship. Prof B R Mehta acknowledges the support of the Schlumberger chair professorship. M V also acknowledges the support of DST-FIST Raman facility. ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:167843 |
Serial |
6567 |
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| Permanent link to this record |
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Author |
Parsons, T.G.; Hadermann, J.; Halasyamani, P.S.; Hayward, M.A. |
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Title |
Preparation of the noncentrosymmetric ferrimagnetic phase La0.9Ba0.1Mn0.96O2.43 by topochemical reduction |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Solid State Chemistry |
Abbreviated Journal |
J Solid State Chem |
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Volume |
287 |
Issue |
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Pages |
121356-121357 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Topochemical reduction of La0.9Ba0.1MnO3 with NaH at 225 degrees C yields the brownmillerite phase La0.9Ba0.1MnO2.5. However, reduction with CaH2 at 435 degrees C results in the formation of La0.9Ba0.1Mn0.96O2.43 via the deintercalation of both oxide anions and manganese cations from the parent perovskite phase. Electron and neutron diffraction data reveal La0.9Ba0.1Mn0.96O2.43 adopts a complex noncentrosymmetric structure, described in space group I23, confirmed by SHG measurements. Low-temperature neutron diffraction data reveal La0.9Ba0.1Mn0.96O2.43 adopts an ordered magnetic structure in which all the nearest neighbor interactions are antiferromagnetic. However, the presence of ordered manganese cation-vacancies results in a net ferrimagnetic structure with net saturated moment of 0.157(2) mu B per manganese center. |
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Wos |
000533632700029 |
Publication Date |
2020-04-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.3 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
; We thank the EPSRC for funding this work and E. Suard for assisting with the collection of the neutron powder diffraction data. PSH thanks the Welch Foundation (Grant E-1457) for support. ; |
Approved |
Most recent IF: 3.3; 2020 IF: 2.299 |
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Call Number |
UA @ admin @ c:irua:169450 |
Serial |
6583 |
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Author |
Han, Y.; Zeng, Y.; Hendrickx, M.; Hadermann, J.; Stephens, P.W.; Zhu, C.; Grams, C.P.; Hemberger, J.; Frank, C.; Li, S.; Wu, M.X.; Retuerto, M.; Croft, M.; Walker, D.; Yao, D.-X.; Greenblatt, M.; Li, M.-R. |
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Title |
Universal a-cation splitting in LiNbO₃-type structure driven by intrapositional multivalent coupling |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of The American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
142 |
Issue |
15 |
Pages |
7168-7178 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Understanding the electric dipole switching in multiferroic materials requires deep insight of the atomic-scale local structure evolution to reveal the ferroelectric mechanism, which remains unclear and lacks a solid experimental indicator in high-pressure prepared LiNbO3-type polar magnets. Here, we report the discovery of Zn-ion splitting in LiNbO3-type Zn2FeNbO6 established by multiple diffraction techniques. The coexistence of a high-temperature paraelectric-like phase in the polar Zn2FeNbO6 lattice motivated us to revisit other high-pressure prepared LiNbO3-type A(2)BB'O-6 compounds. The A-site atomic splitting (similar to 1.0-1.2 angstrom between the split-atom pair) in B/B'-mixed Zn2FeTaO6 and O/N-mixed ZnTaO2N is verified by both powder X-ray diffraction structural refinements and high angle annular dark field scanning transmission electron microscopy images, but is absent in single-B-site ZnSnO3. Theoretical calculations are in good agreement with experimental results and suggest that this kind of A-site splitting also exists in the B-site mixed Mn-analogues, Mn2FeMO6 (M = Nb, Ta) and anion-mixed MnTaO2N, where the smaller A-site splitting (similar to 0.2 angstrom atomic displacement) is attributed to magnetic interactions and bonding between A and B cations. These findings reveal universal A-site splitting in LiNbO3-type structures with mixed multivalent B/B', or anionic sites, and the splitting-atomic displacement can be strongly suppressed by magnetic interactions and/or hybridization of valence bands between d electrons of the A- and B-site cations. |
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Wos |
000526300600046 |
Publication Date |
2020-03-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0002-7863 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
15 |
Times cited |
1 |
Open Access |
Not_Open_Access |
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Notes |
; This work was supported by the National Science Foundation of China (NSFC-21875287), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2017ZT07C069), and an NSF-DMR-1507252 grant (U.S.). Use of the NSLS, Brookhaven National Laboratory, was supported by the DOE BES (DE-AC02-98CH10886). M.R. is thankful for the Spanish Juan de la Cierva grant FPDI-2013-17582. Y.Z. and D.-X.Y. are supported by NKRDPC-2018YFA0306001, NKRDPC-2017YFA0206203, NSFC-11974432, NSFG-2019A1515011337, the National Supercomputer Center in Guangzhou, and the Leading Talent Program of Guangdong Special Projects. Work on IOP, CAS, was supported by NSFC and MOST grants. A portion of this research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. J.H. and M.H. thank the FWO for support for the electron microscopy studies through grant G035619N. We thank beamline BL14B1 (Shanghai Synchrotron Radiation Facility) for providing beam time and help during the experiments. ; |
Approved |
Most recent IF: 15; 2020 IF: 13.858 |
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Call Number |
UA @ admin @ c:irua:170294 |
Serial |
6646 |
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| Permanent link to this record |
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Author |
Xu, X.; Jones, M.A.; Cassidy, S.J.; Manuel, P.; Orlandi, F.; Batuk, M.; Hadermann, J.; Clarke, S.J. |
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Title |
Magnetic Ordering in the Layered Cr(II) Oxide Arsenides Sr2CrO2Cr2As2and Ba2CrO2Cr2As2 |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
59 |
Issue |
21 |
Pages |
15898-15912 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Sr2CrO2Cr2As2 and Ba2CrO2Cr2As2 with Cr2+ ions in CrO2 sheets and in CrAs layers crystallize with the Sr2Mn3Sb2O2 structure (space group I4/mmm, Z = 2) and lattice parameters a = 4.00800(2) Å, c = 18.8214(1) Å (Sr2CrO2Cr2As2) and a = 4.05506(2) Å, c = 20.5637(1) Å (Ba2CrO2Cr2As2) at room temperature. Powder neutron diffraction reveals checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the arsenide layers below TN1Sr, of 600(10) K (Sr2CrO2Cr2As2) and TN1Ba 465(5) K (Ba2CrO2Cr2As2) with the moments initially directed perpendicular to the layers in both compounds. Checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the oxide layer below 230(5) K for Ba2CrO2Cr2As2 occurs with these moments also perpendicular to the layers, consistent with the orientation preferences of d4 moments in the two layers. In contrast, below 330(5) K in Sr2CrO2Cr2As2, the oxide layer Cr2+ moments are initially oriented in the CrO2 plane; but on further cooling, these moments rotate to become perpendicular to the CrO2 planes, while the moments in the arsenide layers rotate by 90° with the moments on the two sublattices remaining orthogonal throughout [behavior recently reported independently by Liu et al. [Liu et al. Phys. Rev. B 2018, 98, 134416]]. In Sr2CrO2Cr2As2, electron diffraction and high resolution powder X-ray diffraction data show no evidence for a structural distortion that would allow the two Cr2+ sublattices to couple, but high resolution neutron powder diffraction data suggest a small incommensurability between the magnetic structure and the crystal structure, which may account for the coupling of the two sublattices and the observed spin reorientation. The saturation values of the Cr2+ moments in the CrO2 layers (3.34(1) μB (for Sr2CrO2Cr2As2) and 3.30(1) μB (for Ba2CrO2Cr2As2)) are larger than those in the CrAs layers (2.68(1) μB for Sr2CrO2Cr2As2 and 2.298(8) μB for Ba2CrO2Cr2As2) reflecting greater covalency in the arsenide layers. |
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Place of Publication |
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Wos |
000588738100035 |
Publication Date |
2020-11-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
We thank the UK EPSRC (EP/M020517/1 and EP/P018874/ 1) and the Leverhulme Trust (RPG-2014-221) for funding and the ISIS pulsed neutron and muon source (RB1610357 and RB1700075) and the Diamond Light Source Ltd. (EE13284 and EE18786) for the award of beam time. We thank Dr. A. Baker and Dr. C. Murray for support on I11. |
Approved |
Most recent IF: 4.6; 2020 IF: 4.857 |
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Call Number |
EMAT @ emat @c:irua:176058 |
Serial |
6704 |
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Author |
Kamminga, M.E.; Batuk, M.; Hadermann, J.; Clarke, S.J. |
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Title |
Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Communications Materials |
Abbreviated Journal |
Commun Mater |
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Volume |
1 |
Issue |
1 |
Pages |
82 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Topological superconductivity is of great contemporary interest and has been proposed in doped Bi<sub>2</sub>Se<sub>3</sub>, in which electron-donating atoms such as Cu, Sr or Nb have been intercalated into the Bi<sub>2</sub>Se<sub>3</sub>structure. For Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>, with<italic>T</italic><sub>c</sub> ~ 3 K, it is assumed in the literature that Nb is inserted in the van der Waals gap. However, in this work an alternative origin for the superconductivity in Nb-doped Bi<sub>2</sub>Se<sub>3</sub>is established. In contrast to previous reports, it is deduced that Nb intercalation in Bi<sub>2</sub>Se<sub>3</sub>does not take place. Instead, the superconducting behaviour in samples of nominal composition Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>results from the (BiSe)<sub>1.10</sub>NbSe<sub>2</sub>misfit phase that is present in the sample as an impurity phase for small<italic>x</italic>(0.01 ≤ <italic>x</italic> ≤ 0.10) and as a main phase for large<italic>x</italic>(<italic>x</italic> = 0.50). The structure of this misfit phase is studied in detail using a combination of X-ray diffraction and transmission electron microscopy techniques. |
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Place of Publication |
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Wos |
000610580800001 |
Publication Date |
2020-11-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2662-4443 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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Notes |
M.E.K. was supported by the Netherlands Organisation for Scientific Research (NWO, grant code 019.181EN.003). We also acknowledge support from the EPSRC (EP/ R042594/1, EP/P018874/1, EP/M020517/1) and the Leverhulme Trust (RPG-2018-377). J.H. acknowledges support from the University of Antwerp through BOF Grant No. 31445. We thank DLS Ltd for beam time (EE18786), Dr Clare Murray for assistance on I11 and Dr Jon Wade from the Department of Earth Sciences, University of Oxford for performing the SEM measurements. We also thank Dr Michal Dušak and Dr Václav Petřiček for their advice concerning the use of the Jana2006 software. |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @c:irua:176116 |
Serial |
6705 |
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| Permanent link to this record |
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Author |
Chizhov, As.; Rumyantseva, Mn.; Drozdov, Ka.; Krylov, Iv.; Batuk, M.; Hadermann, J.; Filatova, Dg.; Khmelevsky, No.; Kozlovsky, Vf.; Maltseva, Ln.; Gaskov, Am. |
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Title |
Photoresistive gas sensor based on nanocrystalline ZnO sensitized with colloidal perovskite CsPbBr3 nanocrystals |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
329 |
Issue |
|
Pages |
129035 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The development of sensor materials of which gas sensitivity activates under light illumination is of great importance for the design of portable gas analyzers with low power consumption. In the present work a ZnO/CsPbBr3 nanocomposite based on nanocrystalline ZnO and colloidal cubic-shaped perovskite CsPbBr3 nanocrystals (NCs) capped by oleic acide and oleylamine was synthesized. The individual materials and obtained nanocomposite are characterized by x-ray diffraction, low-temperature nitrogen adsorption, x-ray photoelectron spectroscopy, high angle annular dark field scanning transmission electron microscopy with energy-dispersive Xray spectroscopy mapping and UV-vis absorption spectroscopy. The spectral dependence of the photoconductivity of the ZnO/CsPbBr3 nanocomposite reveals a well-defined peak that strongly correlates with the its optical absorption spectrum. The nanocomposite ZnO/CsPbBr3 shows enhanced photoresponse under visible light illumination (lambda(max) = 470 nm, 8 mW/cm(2)) in air, oxygen and argone, compared with pure nanocrystalline ZnO. Under periodic illumination in the temperature range of 25-100 degrees C, the ZnO/CsPbBr3 nanocomposite shows a sensor response to 0.5-3.0 ppm NO2, unlike pure nanocrystalline ZnO matrix, which demonstrates sensor sensitivity to NO2 under the same conditions above 100 degrees C. The effects of humidity on the sensor signal and photoresponse are also discussed. |
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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 |
000612060700009 |
Publication Date |
2020-10-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
5.401 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
The reported study was funded by RFBR according to the research project N◦ 18-33-01004 and in part by a grant from the St. Petersburg State University – Event 3-2018 (id: 46380300). Element mapping for sensors were supported by M.V. Lomonosov Moscow State University Program of Development (X-ray fluorescence spectrometer Tornado M4 plus). |
Approved |
Most recent IF: 5.401 |
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| |
Call Number |
EMAT @ emat @c:irua:176123 |
Serial |
6707 |
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| Permanent link to this record |
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Author |
Skaggs, C.M.; Kang, C.-J.; Perez, C.J.; Hadermann, J.; Emge, T.J.; Frank, C.E.; Pak, C.; Lapidus, S.H.; Walker, D.; Kotliar, G.; Kauzlarich, S.M.; Tan, X.; Greenblatt, M. |
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Title |
Ambient and high pressure CuNiSb₂ : metal-ordered and metal-disordered NiAs-type derivative pnictides |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
59 |
Issue |
19 |
Pages |
14058-14069 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The mineral Zlatogorite, CuNiSb2, was synthesized in the laboratory for the first time by annealing elements at ambient pressure (CuNiSb2-AP). Rietveld refinement of synchrotron powder X-ray diffraction data indicates that CuNiSb2-AP crystallizes in the NiAs-derived structure (P (3) over bar m1, #164) with Cu and Ni ordering. The structure consists of alternate NiSb6 and CuSb6 octahedral layers via face-sharing. The formation of such structure instead of metal disordered NiAs-type structure (P6(3)/mmc, #194) is validated by the lower energy of the ordered phase by first-principle calculations. Interatomic crystal orbital Hamilton population, electron localization function, and charge density analysis reveal strong Ni-Sb, Cu-Sb, and Cu-Ni bonding and long weak Sb-Sb interactions in CuNiSb2-AP. The magnetic measurement indicates that CuNiSb2-AP is Pauli paramagnetic. First-principle calculations and experimental electrical resistivity measurements reveal that CuNiSb2-AP is a metal. The low Seebeck coefficient and large thermal conductivity suggest that CuNiSb2 is not a potential thermoelectric material. Single crystals were grown by chemical vapor transport. The high pressure sample (CuNiSb2-8 GPa) was prepared by pressing CuNiSb2-AP at 700 degrees C and 8 GPa. However, the structures of single crystal and CuNiSb2-8 GPa are best fit with a disordered metal structure in the P (3) over bar m1 space group, corroborated by transmission electron microscopy. |
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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 |
000580381700028 |
Publication Date |
2020-09-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
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Approved |
Most recent IF: 4.6; 2020 IF: 4.857 |
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| |
Call Number |
UA @ admin @ c:irua:174331 |
Serial |
6714 |
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| Permanent link to this record |
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Author |
Volykhov, A.A.; Frolov, A.S.; Neudachina, V.S.; Vladimirova, N.V.; Gerber, E.; Callaert, C.; Hadermann, J.; Khmelevsky, N.O.; Knop-Gericke, A.; Sanchez-Barriga, J.; Yashina, L.V. |
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Title |
Impact of ordering on the reactivity of mixed crystals of topological insulators with anion substitution: Bi₂SeTe₂ and Sb₂SeTe₂ |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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| |
Volume |
541 |
Issue |
|
Pages |
148490 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Three-dimensional topological insulators are exotic materials with unique properties. Tetradymite type binary chalcogenides of bismuth and antimony, as well as their mixed crystals, belong to prototypical TIs. Potential device applications of these materials require in-depth knowledge of their stability in the ambient atmosphere and other media maintained during their processing. Here we investigated the reactivity of mixed crystals with anion substitution, Bi-2(Se1-xTex)(3) and Sb2(Se1-xTex)(3), towards molecular oxygen using both in situ and ex situ X-ray photoelectron spectroscopy. The results indicate that, in contrast to cation substitution, partial substitution of tellurium by selenium atoms leads to anomalously high surface reactivity, which even exceeds that of the most reactive binary constituent. We attribute this effect to anion ordering that essentially modifies the bond geometry, especially the respective bond angles as modeled by DFT. |
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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 |
000608492900003 |
Publication Date |
2020-11-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.387 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 3.387 |
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| |
Call Number |
UA @ admin @ c:irua:176067 |
Serial |
6728 |
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| Permanent link to this record |
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Author |
Ryabova, A.S.; Istomin, S.Y.; Dosaev, K.A.; Bonnefont, A.; Hadermann, J.; Arkharova, N.A.; Orekhov, A.S.; Sena, R.P.; Saveleva, V.A.; Kerangueven, G.; Antipov, E., V.; Savinova, E.R.; Tsirlina, G.A. |
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Title |
Mn₂O₃ oxide with bixbyite structure for the electrochemical oxygen reduction reaction in alkaline media : highly active if properly manipulated |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Electrochimica Acta |
Abbreviated Journal |
Electrochim Acta |
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| |
Volume |
367 |
Issue |
|
Pages |
137378 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We consider compositional and structural factors which can affect the activity of bixbyite alpha-Mn2O3 towards the oxygen reduction reaction (ORR) and the stability of this oxide in alkaline solution. We compare electrochemistry of undoped, Fe and Al-doped alpha-Mn2O3 with bixbyite structure and braunite Mn7SiO12 having bixbyite-related crystal structure, using the rotating disk electrode (RDE), the rotating ring-disk electrode (RRDE), and cyclic voltammetry (CV) techniques. All manganese oxides under study are stable in the potential range between the ORR onset and ca. 0.7 V vs. Reversible Hydrogen Electrode (RHE). It is found that any changes introduced in the bixbyite structure and/or composition of alpha-Mn2O3 lead to an activity drop in both the oxygen reduction and hydrogen peroxide reactions in this potential interval. For the hydrogen peroxide reduction reaction these modifications also result in a change in the nature of the rate-determining step. The obtained results confirm that due to its unique crystalline structure undoped alpha-Mn2O3 is the most ORR active (among currently available) Mn oxide catalyst and favor the assumption of the key role of the (111) surface of alpha-Mn2O3 in the very high activity of this material towards the ORR. (C) 2020 Elsevier Ltd. All rights reserved. |
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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 |
000607621500013 |
Publication Date |
2020-10-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0013-4686 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.798 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.798 |
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Call Number |
UA @ admin @ c:irua:176080 |
Serial |
6731 |
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| Permanent link to this record |
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Author |
Hendrickx, M.; Tang, Y.; Hunter, E.C.; Battle, P.D.; Hadermann, J. |
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Title |
Structural and magnetic properties of the perovskites A₂LaFe₂SbO₉ (A = Ca, Sr, Ba) |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of Solid State Chemistry |
Abbreviated Journal |
J Solid State Chem |
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| |
Volume |
295 |
Issue |
|
Pages |
121914 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Polycrystalline samples of A(2)LaFe(2)SbO(9) (A = Ca, Sr, Ba) perovskites appeared monophasic to X-ray or neutron powder diffraction but a single-crystal study utilising transmission electron microscopy revealed a greater level of complexity. Although local charge balance is maintained, compositional and structural variations are present among and within the submicron-sized crystals. Despite the inhomogeneity, A = Ca is monophasic with a partially-ordered distribution of Fe3+ and Sb5+ cations across two crystallographically-distinct octahedral sites, i.e. Ca2La(Fe1.25Sb0.25)(2d) (Fe0.75Sb0.75)(2c)O-9. For A = Sr or Ba, the inhomogeneities result in differences in the filling patterns of the octahedra and the ordering of the B cations. Particles of A = Sr contain a phase (Fe:Sb similar to 2:1) without B cation ordering and one (Fe:Sb similar to 1:1) with B cation ordering. Monophasic A = Ba lacks long-range cation order although ordered nanodomains are present within the disordered phase. The temperature dependence of the magnetic properties of each sample is discussed. |
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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 |
000615711800013 |
Publication Date |
2020-12-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.299 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 2.299 |
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Call Number |
UA @ admin @ c:irua:176663 |
Serial |
6739 |
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| Permanent link to this record |
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Author |
Vishwakarma, M.; Kumar, M.; Hendrickx, M.; Hadermann, J.; Singh, A.P.; Batra, Y.; Mehta, B.R. |
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Title |
Enhancing the hydrogen evolution properties of kesterite absorber by Si-doping in the surface of CZTS thin film |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
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Volume |
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Issue |
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Pages |
2002124 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work, the effects of Si-doping in Cu2ZnSnS4 are examined computationally and experimentally. The density functional theory calculations show that an increasing concentration of Si (from x = 0 to x = 1) yields a band gap rise due to shifting of the conduction band minimum towards higher energy states in the Cu2Zn(Sn1-xSix)S-4. CZTSiS thin film prepared by co-sputtering process shows Cu2Zn(Sn1-xSix)S-4 (Si-rich) and Cu2ZnSnS4 (S-rich) kesterite phases on the surface and in the bulk of the sample, respectively. A significant change in surface electronic properties is observed in CZTSiS thin film. Si-doping in CZTS inverts the band bending at grain-boundaries from downward to upward and the Fermi level of CZTSiS shifts upward. Further, the coating of the CdS and ZnO layer improves the photocurrent to approximate to 5.57 mA cm(-2) at -0.41 V-RHE in the CZTSiS/CdS/ZnO sample, which is 2.39 times higher than that of pure CZTS. The flat band potential increases from CZTS approximate to 0.43 V-RHE to CZTSiS/CdS/ZnO approximate to 1.31 V-RHE indicating the faster carrier separation process at the electrode-electrolyte interface in the latter sample. CdS/ZnO layers over CZTSiS significantly reduce the charge transfer resistance at the semiconductor-electrolyte interface. |
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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 |
000635804900001 |
Publication Date |
2021-04-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2196-7350 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.279 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.279 |
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| |
Call Number |
UA @ admin @ c:irua:177688 |
Serial |
6780 |
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| Permanent link to this record |
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Author |
Bhaskar, G.; Gvozdetskyi, V.; Batuk, M.; Wiaderek, K.M.; Sun, Y.; Wang, R.; Zhang, C.; Carnahan, S.L.; Wu, X.; Ribeiro, R.A.; Bud'ko, S.L.; Canfield, P.C.; Huang, W.; Rossini, A.J.; Wang, C.-Z.; Ho, K.-M.; Hadermann, J.; Zaikina, J., V |
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Title |
Topochemical deintercalation of Li from layered LiNiB : toward 2D MBene |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of The American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
143 |
Issue |
11 |
Pages |
4213-4223 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The pursuit of two-dimensional (2D) borides, MBenes, has proven to be challenging, not the least because of the lack of a suitable precursor prone to the deintercalation. Here, we studied room-temperature topochemical deintercalation of lithium from the layered polymorphs of the LiNiB compound with a considerable amount of Li stored in between [NiB] layers (33 at. % Li). Deintercalation of Li leads to novel metastable borides (Li similar to 0.5NiB) with unique crystal structures. Partial removal of Li is accomplished by exposing the parent phases to air, water, or dilute HCl under ambient conditions. Scanning transmission electron microscopy and solid-state Li-7 and B-1(1) NMR spectroscopy, combined with X-ray pair distribution function (PDF) analysis and DFT calculations, were utilized to elucidate the novel structures of (Li similar to 0.5NiB) and the mechanism of Li-deintercalation. We have shown that the deintercalation of Li proceeds via a “zip-lock” mechanism, leading to the condensation of single [NiB] layers into double or triple layers bound via covalent bonds, resulting in structural fragments with Li[NiB](2) and Li[NiB](3) compositions. The crystal structure of Li similar to 0.5NiB is best described as an intergrowth of the ordered single [NiB], double [NiB](2), or triple [NiB](3) layers alternating with single Li layers; this explains its structural complexity. The formation of double or triple [NiB] layers induces a change in the magnetic behavior from temperature-independent paramagnets in the parent LiNiB compounds to the spin-glassiness in the deintercalated Li similar to 0.5NiB counterparts. LiNiB compounds showcase the potential to access a plethora of unique materials, including 2D MBenes (NiB). |
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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 |
000634761500021 |
Publication Date |
2021-03-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0002-7863 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.858 |
Times cited |
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Open Access |
Not_Open_Access |
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| |
Notes |
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Approved |
Most recent IF: 13.858 |
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Call Number |
UA @ admin @ c:irua:177697 |
Serial |
6790 |
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| Permanent link to this record |
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Author |
Feng, H.L.; Kang, C.-J.; Manuel, P.; Orlandi, F.; Su, Y.; Chen, J.; Tsujimoto, Y.; Hadermann, J.; Kotliar, G.; Yamaura, K.; McCabe, E.E.; Greenblatt, M. |
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Title |
Antiferromagnetic order breaks inversion symmetry in a metallic double perovskite, Pb₂NiOsO₆ |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Chemistry Of Materials |
Abbreviated Journal |
Chem Mater |
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Volume |
33 |
Issue |
11 |
Pages |
4188-4195 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A polycrystalline sample of Pb2NiOsO6 was synthesized under high-pressure (6 GPa) and high-temperature (1575 K) conditions. Pb2NiOsO6 crystallizes in a monoclinic double perovskite structure with a centrosymmetric space group P2(1)/n at room temperature. Pb2NiOsO6 is metallic down to 2 K and shows a single antiferromagnetic (AFM) transition at T-N = 58 K. Pb2NiOsO6 is a new example of a metallic and AFM oxide with three-dimensional connectivity. Neutron powder diffraction and first-principles calculation studies indicate that both Ni and Os moments are ordered below T-N and the AFM magnetic order breaks inversion symmetry. This loss of inversion symmetry driven by AFM order is unusual in metallic systems, and the 3d-Sd double-perovskite oxides represent a new class of noncentrosymmetric AFM metallic oxides. |
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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 |
000661521800032 |
Publication Date |
2021-05-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756; 1520-5002 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 9.466 |
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Call Number |
UA @ admin @ c:irua:179679 |
Serial |
6854 |
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| Permanent link to this record |
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Author |
Mallick, S.; Khalsa, G.; Kaaret, J.Z.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Benedek, N.A.; Hayward, M.A. |
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Title |
The influence of the 6s² configuration of Bi³+ on the structures of A ' BiNb₂O₇ (A ' = Rb, Na, Li) layered perovskite oxides |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
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| |
Volume |
50 |
Issue |
42 |
Pages |
15359-15369 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The 'hybrid improper' mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7 and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+ cations which are often observed to stabilize acentric crystal structures due to their 6s(2) electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7 and LiBiNb2O7 adopt polar crystal structures (space groups I2cm and B2cm respectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+ cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+ cations with Nd3+ cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7 (space group P2(1)2(1)2(1)) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+ cations. |
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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 |
000706651100001 |
Publication Date |
2021-10-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1477-9234 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:182584 |
Serial |
6893 |
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| Permanent link to this record |
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Author |
Mallick, S.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Hayward, M.A. |
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Title |
The crystal and defect structures of polar KBiNb2O7 |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
51 |
Issue |
5 |
Pages |
1866-1873 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0. ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately an ~11% chance of being defective – a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault. |
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Place of Publication |
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Editor |
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Wos |
000741540300001 |
Publication Date |
2022-01-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
4 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford/Warwick Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE18786). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC (RB 2000148). SM thanks Somerville College for an Oxford Ryniker Lloyd scholarship. PSH and WZ thank the National Science Foundation (DMR-2002319) for support. |
Approved |
Most recent IF: 4 |
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Call Number |
EMAT @ emat @c:irua:185504 |
Serial |
6951 |
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Author |
Missen, O.P.; Mills, S.J.; Canossa, S.; Hadermann, J.; Nenert, G.; Weil, M.; Libowitzky, E.; Housley, R.M.; Artner, W.; Kampf, A.R.; Rumsey, M.S.; Spratt, J.; Momma, K.; Dunstan, M.A. |
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Title |
Polytypism in mcalpineite : a study of natural and synthetic Cu₃TeO₆ |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials (Online) |
Abbreviated Journal |
Acta Crystallogr B |
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Volume |
78 |
Issue |
1 |
Pages |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Synthetic and naturally occurring forms of tricopper orthotellurate, (Cu3TeO6)-Te-II-O-IV (the mineral mcalpineite) have been investigated by 3D electron diffraction (3D ED), X-ray powder diffraction (XRPD), Raman and infrared (IR) spectroscopic measurements. As a result of the diffraction analyses, (Cu3TeO6)-Te-II-O-IV is shown to occur in two polytypes. The higher-symmetric (Cu3TeO6)-Te-II-O-IV-1C polytype is cubic, space group 1a (3) over bar, with a = 9.537 (1) angstrom and V = 867.4 (3) angstrom(3) as reported in previous studies. The 1C polytype is a well characterized structure consisting of alternating layers of (CuO6)-O-II octahedra and both (CuO6)-O-II and (TeO6)-O-VI octahedra in a patchwork arrangement. The structure of the lower-symmetric orthorhombic (Cu3TeO6)-Te-II-O-IV-2O polytype was determined for the first time in this study by 3D ED and verified by Rietveld refinement. The 2O polytype crystallizes in space group Pcca, with a = 9.745 (3) angstrom, b = 9.749 (2) angstrom, c = 9.771 (2) angstrom and V = 928.3 (4) angstrom(3) . High-precision XRPD data were also collected on (Cu3TeO6)-Te-II-O-IV-2O to verify the lower-symmetric structure by performing a Rietveld refinement. The resultant structure is identical to that determined by 3D ED, with unit-cell parameters a = 9.56157 (19) angstrom, b = 9.55853 (11) angstrom, c = 9.62891 (15) angstrom and V = 880.03 (2) angstrom(3) . The lower symmetry of the 2O polytype is a consequence of a different cation ordering arrangement, which involves the movement of every second (CuO6)-O-II and (TeO6)-O-VI octahedral layer by (1/4, 1/4, 0), leading to an offset of (TeO6)-O-VI and (CuO6)-O-II octahedra in every second layer giving an ABAB* stacking arrangement. Syntheses of (Cu3TeO6)-Te-II-O-IV showed that low-temperature (473 K) hydrothermal conditions generally produce the 2O polytype. XRPD measurements in combination with Raman spectroscopic analysis showed that most natural mcalpineite is the orthorhombic 2O polytype. Both XRPD and Raman spectroscopy measurements may be used to differentiate between the two polytypes of (Cu3TeO6)-Te-II-O-IV. In Raman spectroscopy, (Cu3TeO6)-Te-II-O-IV-1C has a single strong band around 730 cm(-1), whereas (Cu3TeO6)-Te-II-O-IV-2O shows a broad double maximum with bands centred around 692 and 742 cm(-1). |
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Place of Publication |
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Language |
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Wos |
000752899700003 |
Publication Date |
2022-01-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2052-5206 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.9 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 1.9 |
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Call Number |
UA @ admin @ c:irua:186529 |
Serial |
6962 |
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Author |
Savina, A.A.; Saiutina, V.V.; Morozov, A.V.; Boev, A.O.; Aksyonov, D.A.; Dejoie, C.; Batuk, M.; Bals, S.; Hadermann, J.; Abakumov, A.M. |
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Title |
Chemistry, local molybdenum clustering, and electrochemistry in the Li2+xMo1-xO3 solid solutions |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
61 |
Issue |
14 |
Pages |
5637-5652 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A broad range of cationic nonstoichiometry has been demonstratedfor the Li-rich layered rock-salt-type oxide Li2MoO3, which has generally been considered as a phase with a well-defined chemical composition. Li2+xMo1-xO3(-0.037 <= x <= 0.124) solid solutions were synthesized via hydrogen reduction ofLi2MoO4in the temperature range of 650-1100 degrees C, withxdecreasing with theincrease of the reduction temperature. The solid solutions adopt a monoclinicallydistorted O3-type layered average structure and demonstrate a robust localordering of the Li cations and Mo3triangular clusters within the mixed Li/Mocationic layers. The local structure was scrutinized in detail by electron diffractionand aberration-corrected scanning transmission electron microcopy (STEM),resulting in an ordering model comprising a uniform distribution of the Mo3clusters compatible with local electroneutrality and chemical composition. The geometry of the triangular clusters with their oxygenenvironment (Mo3O13groups) has been directly visualized using differential phase contrast STEM imaging. The established localstructure was used as input for density functional theory (DFT)-based calculations; they support the proposed atomic arrangementand provide a plausible explanation for the staircase galvanostatic charge profiles upon electrochemical Li+extraction fromLi2+xMo1-xO3in Li cells. According to DFT, all electrochemical capacity in Li2+xMo1-xO3solely originates from the cationic Moredox process, which proceeds via oxidation of the Mo3triangular clusters into bent Mo3chains where the electronic capacity of the clusters depends on the initial chemical composition and Mo oxidation state defining the width of the first charge low-voltageplateau. Further oxidation at the high-voltage plateau proceeds through decomposition of the Mo3chains into Mo2dimers and further into individual Mo6+cations |
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Wos |
000789034200023 |
Publication Date |
2022-04-01 |
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Series Editor |
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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 |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.6 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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Notes |
The authors acknowledge Russian Science Foundation (grant 20-43-01012) and Research Foundation Flanders (FWO Vlaanderen, project number G0F1320N) for financial support. The authors are grateful to AICF of Skoltech for providing access to electron microscopy equipment. The authors are grateful to Prof. G. Van Tendeloo for discussing the results. |
Approved |
Most recent IF: 4.6 |
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Call Number |
UA @ admin @ c:irua:188631 |
Serial |
7079 |
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Author |
Poppe, R.; Vandemeulebroucke, D.; Neder, R.B.; Hadermann, J. |
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Title |
Quantitative analysis of diffuse electron scattering in the lithium-ion battery cathode material Li1.2Ni0.13Mn0.54Co0.13O2 |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
IUCrJ |
Abbreviated Journal |
Iucrj |
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Volume |
9 |
Issue |
5 |
Pages |
695-704 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In contrast to perfectly periodic crystals, materials with short-range order produce diffraction patterns that contain both Bragg reflections and diffuse scattering. To understand the influence of short-range order on material properties, current research focuses increasingly on the analysis of diffuse scattering. This article verifies the possibility to refine the short-range order parameters in submicrometre-sized crystals from diffuse scattering in single-crystal electron diffraction data. The approach was demonstrated on Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>, which is a state-of-the-art cathode material for lithium-ion batteries. The intensity distribution of the 1D diffuse scattering in the electron diffraction patterns of Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>depends on the number of stacking faults and twins in the crystal. A model of the disorder in Li<sub>1.2</sub>Ni<sub>0.13</sub>Mn<sub>0.54</sub>Co<sub>0.13</sub>O<sub>2</sub>was developed and both the stacking fault probability and the percentage of the different twins in the crystal were refined using an evolutionary algorithm in<italic>DISCUS</italic>. The approach was applied on reciprocal space sections reconstructed from 3D electron diffraction data since they exhibit less dynamical effects compared with in-zone electron diffraction patterns. A good agreement was achieved between the calculated and the experimental intensity distribution of the diffuse scattering. The short-range order parameters in submicrometre-sized crystals can thus successfully be refined from the diffuse scattering in single-crystal electron diffraction data using an evolutionary algorithm in<italic>DISCUS</italic>. |
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Wos |
000852551800018 |
Publication Date |
2022-09-01 |
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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 |
2052-2525 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.9 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
The research leading to these results has received funding from the Research Foundation Flanders, G035619N G040116N ; |
Approved |
Most recent IF: 3.9 |
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Call Number |
EMAT @ emat @c:irua:190647 |
Serial |
7105 |
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Author |
Lopez-Garcia, C.; Canossa, S.; Hadermann, J.; Gorni, G.; Oropeza, F.E.; de la Pena O'Shea, V.A.; Iglesias, M.; Monge, M.A.; Gutierrez-Puebla, E.; Gandara, F. |
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Title |
Heterometallic molecular complexes act as messenger building units to encode desired metal-atom combinations to multivariate metal-organic frameworks |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
144 |
Issue |
36 |
Pages |
16262-16266 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A novel synthetic approach is described for the targeted preparation of multivariate metal-organic frameworks (MTV-MOFs) with specific combinations of metal elements. This methodology is based on the use of molecular complexes that already comprise desired metal-atom combinations, as building units for the MTV-MOF synthesis. These units are transformed into the MOF structural constituents through a ligand/linker exchange process that involves structural modifications while preserving their origina l l y encoded atomic combination. Thus, through the use of heterometalli c ring-shaped molecules combining gallium and nickel or cobalt, we have obtained MOFs with identical combinations of the metal elements, now incorporated in the rod-shaped secondary building unit, as confirmed with a combination of X-ray and electron diffraction, electron microscopy, and X-ray absorption spectroscopy techniques. |
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Place of Publication |
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Wos |
000841435900001 |
Publication Date |
2022-08-12 |
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Series Editor |
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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 |
0002-7863 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
15 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 15 |
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Call Number |
UA @ admin @ c:irua:190023 |
Serial |
7169 |
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| Permanent link to this record |
