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Author	Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Shpanchenko, R.V.; Geibel, C.; Rosner, H.
Title	Frustrated square lattice with spatial anisotropy: crystal structure and magnetic properties of PbZnVO(PO₄)₂			Type	A1 Journal article
Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	81	Issue	17	Pages	174424,1-174424,13
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Crystal structure and magnetic properties of the layered vanadium phosphate PbZnVO(PO4)2 are studied using x-ray powder diffraction, magnetization and specific-heat measurements, as well as band-structure calculations. The compound resembles AA′VO(PO4)2 vanadium phosphates and fits to the extended frustrated square-lattice model with the couplings J1, J1′ between nearest neighbors and J2, J2′ between next-nearest neighbors. The temperature dependence of the magnetization yields estimates of averaged nearest-neighbor and next-nearest-neighbor couplings, J̅ 1≃−5.2 K and J̅ 2≃10.0 K, respectively. The effective frustration ratio α=J̅ 2/J̅ 1 amounts to −1.9 and suggests columnar antiferromagnetic ordering in PbZnVO(PO4)2. Specific-heat data support the estimates of J̅ 1 and J̅ 2 and indicate a likely magnetic ordering transition at 3.9 K. However, the averaged couplings underestimate the saturation field, thus pointing to the spatial anisotropy of the nearest-neighbor interactions. Band-structure calculations confirm the identification of ferromagnetic J1, J1′ and antiferromagnetic J2, J2′ in PbZnVO(PO4)2 and yield (J1′−J1)≃1.1 K in excellent agreement with the experimental value of 1.1 K, deduced from the difference between the expected and experimentally measured saturation fields. Based on the comparison of layered vanadium phosphates with different metal cations, we show that a moderate spatial anisotropy of the frustrated square lattice has minor influence on the thermodynamic properties of the model. We discuss relevant geometrical parameters, controlling the exchange interactions in these compounds and propose a strategy for further design of strongly frustrated square-lattice materials.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000278141600082	Publication Date	2010-05-25
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	27	Open Access
Notes				Approved	Most recent IF: 3.836; 2010 IF: 3.774
Call Number	UA @ lucian @ c:irua:83384			Serial	1294
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Author	Tsirlin, A.A.; Abakumov, A.M.; Van Tendeloo, G.; Rosner, H.
Title	Interplay of atomic displacement in the quantum magnet (CuCI)LaNb₂O₇			Type	A1 Journal article
Year	2010	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	82	Issue	5	Pages	054107,1-054107,12
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We report on the crystal structure of the quantum magnet CuClLaNb2O7 that was controversially described with respect to its structural organization and magnetic behavior. Using high-resolution synchrotron powder x-ray diffraction, electron diffraction, transmission electron microscopy, and band-structure calculations, we solve the room-temperature structure of this compound -CuClLaNb2O7 and find two high-temperature polymorphs. The -CuClLaNb2O7 phase, stable above 640 K, is tetragonal with asub=3.889 Å, csub =11.738 Å, and the space group P4/mmm. In the -CuClLaNb2O7 structure, the Cu and Cl atoms are randomly displaced from the special positions along the 100 directions. The phase asub2asubcsub, space group Pbmm and the phase 2asub2asubcsub, space group Pbam are stable between 640 K and 500 K and below 500 K, respectively. The structural changes at 500 and 640 K are identified as order-disorder phase transitions. The displacement of the Cl atoms is frozen upon the → transformation while a cooperative tilting of the NbO6 octahedra in the phase further eliminates the disorder of the Cu atoms. The low-temperature -CuClLaNb2O7 structure thus combines the two types of the atomic displacements that interfere due to the bonding between the Cu atoms and the apical oxygens of the NbO6 octahedra. The precise structural information resolves the controversy between the previous computation-based models and provides the long-sought input for understanding CuClLaNb2O7 and related compounds with unusual magnetic properties.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000280849400001	Publication Date	2010-08-12
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	13	Open Access
Notes				Approved	Most recent IF: 3.836; 2010 IF: 3.774
Call Number	UA @ lucian @ c:irua:83991			Serial	1706
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Author	Gou, H.; Tsirlin, A.A.; Bykova, E.; Abakumov, A.M.; Van Tendeloo, G.; Richter, A.; Ovsyannikov, S.V.; Kurnosov, A.V.; Trots, D.M.; Konôpková, Z.; Liermann, H.P.; Dubrovinsky, L.; Dubrovinskaia, N.;
Title	Peierls distortion, magnetism, and high hardness of manganese tetraboride			Type	A1 Journal article
Year	2014	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	89	Issue	6	Pages	064108-64109
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure, high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features a monoclinic crystal structure. Its lower symmetry originates from a Peierls distortion of the Mn chains. This distortion nearly opens the gap at the Fermi level, but despite the strong dimerization and the proximity of MnB4 to the insulating state, we find indications for a sizable paramagnetic effective moment of about 1.7 mu(B)/f.u., ferromagnetic spin correlations, and, even more surprisingly, a prominent electronic contribution to the specific heat. However, no magnetic order has been observed in standard thermodynamic measurements down to 2 K. Altogether, this renders MnB4 a structurally simple but microscopically enigmatic material; we argue that its properties may be influenced by electronic correlations.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000332405000002	Publication Date	2014-02-24
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	39	Open Access
Notes				Approved	Most recent IF: 3.836; 2014 IF: 3.736
Call Number	UA @ lucian @ c:irua:115819			Serial	2571
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Author	Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H.
Title	Phase separation and frustrated square lattice magnetism of Na_1.5VOPO₄F_0.5			Type	A1 Journal article
Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	84	Issue	1	Pages	014429-014429,16
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000293247400008	Publication Date	2011-07-28
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	47	Open Access
Notes				Approved	Most recent IF: 3.836; 2011 IF: 3.691
Call Number	UA @ lucian @ c:irua:91770			Serial	2588
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Author	Tsirlin, A.A.; Abakumov, A.M.; Ritter, C.; Henry, P.F.; Janson, O.; Rosner, H.
Title	Short-range order of Br and three-dimensional magnetism in (CuBr)LaNb₂O₇			Type	A1 Journal article
Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	85	Issue	21	Pages	214427
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We present a comprehensive study of the crystal structure, magnetic structure, and microscopic magnetic model of (CuBr)LaNb2O7, the Br analog of the spin-gap quantum magnet (CuCl) LaNb2O7. Despite similar crystal structures and spin lattices, the magnetic behavior and even peculiarities of the atomic arrangement in the Cl and Br compounds are very different. The high- resolution x-ray and neutron data reveal a split position of Br atoms in (CuBr) LaNb2O7. This splitting originates from two possible configurations developed by [CuBr] zigzag ribbons. While the Br atoms are locally ordered in the ab plane, their arrangement along the c direction remains partially disordered. The predominant and energetically more favorable configuration features an additional doubling of the c lattice parameter that was not observed in (CuCl) LaNb2O7. (CuBr) LaNb2O7 undergoes long-range antiferromagnetic ordering at T-N = 32 K, which is nearly 70% of the leading exchange coupling J4 similar or equal to 48 K. The Br compound does not show any experimental signatures of low-dimensional magnetism because the underlying spin lattice is three-dimensional. The coupling along the c direction is comparable to the couplings in the ab plane, even though the shortest Cu-Cu distance along c (11.69 angstrom) is three times larger than nearest-neighbor distances in the ab plane (3.55 angstrom). The stripe antiferromagnetic long-range order featuring columns of parallel spins in the ab plane and antiparallel spins along c is verified experimentally and confirmed by the microscopic analysis.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000305557600002	Publication Date	2012-06-22
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	5	Open Access
Notes				Approved	Most recent IF: 3.836; 2012 IF: 3.767
Call Number	UA @ lucian @ c:irua:100289			Serial	2998
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Author	Abakumov, A.M.; Tsirlin, A.A.; Perez-Mato, J.M.; Petřiček, V.; Rosner, H.; Yang, T.; Greenblatt, M.
Title	Spiral ground state against ferroelectricity in the frustrated magnet BiMnFe₂O₆			Type	A1 Journal article
Year	2011	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	83	Issue	21	Pages	214402-214402,10
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The spiral magnetic structure and underlying spin lattice of BiMnFe2O6 are investigated by low-temperature neutron powder diffraction and density functional theory band structure calculations. In spite of the random distribution of the Mn3+ and Fe3+ cations, this centrosymmetric compound undergoes a transition into an incommensurate antiferromagnetically ordered state below TN≃220 K. The magnetic structure is characterized by the propagation vector k=[0,β,0] with β≃0.14 and the P221211′(0β0)0s0s magnetic superspace symmetry. It comprises antiferromagnetic helixes propagating along the b axis. The magnetic moments lie in the ac plane and rotate about π(1+β)≃204.8-deg angle between the adjacent magnetic atoms along b. The spiral magnetic structure arises from the peculiar frustrated arrangement of exchange couplings in the ab plane. The antiferromagnetic coupling along the c axis cancels the possible electric polarization and prevents ferroelectricity in BiMnFe2O6.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000291197400001	Publication Date	2011-06-03
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	12	Open Access
Notes				Approved	Most recent IF: 3.836; 2011 IF: 3.691
Call Number	UA @ lucian @ c:irua:90080			Serial	3107
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Author	Tsirlin, A.A.; Abakumov, A.M.; Ritter, C.; Rosner, H.
Title	(CuCl)LaTa₂O_\text{7} and quantum phase transition in the (CuX)LaM₂O₇ family (X=Cl, Br; M=Nb, Ta)			Type	A1 Journal article
Year	2012	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	86	Issue	6	Pages	064440-12
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We apply neutron diffraction, high-resolution synchrotron x-ray diffraction, magnetization measurements, electronic structure calculations, and quantum Monte-Carlo simulations to unravel the structure and magnetism of (CuCl)LaTa2O7. Despite the pseudo-tetragonal crystallographic unit cell, this compound features an orthorhombic superstructure, similar to the Nb-containing (CuX)LaNb2O7 with X = Cl and Br. The spin lattice entails dimers formed by the antiferromagnetic fourth-neighbor coupling J(4), as well as a large number of nonequivalent interdimer couplings quantified by an effective exchange parameter J(eff). In (CuCl)LaTa2O7, the interdimer couplings are sufficiently strong to induce the long-range magnetic order with the Neel temperature T-N similar or equal to 7 K and the ordered magnetic moment of 0.53 mu(B), as measured with neutron diffraction. This magnetic behavior can be accounted for by J(eff)/J(4) similar or equal to 1.6 and J(4) similar or equal to 16 K. We further propose a general magnetic phase diagram for the (CuCl)LaNb2O7-type compounds, and explain the transition from the gapped spin-singlet (dimer) ground state in (CuCl)LaNb2O7 to the long-range antiferromagnetic order in (CuCl)LaTa2O7 and (CuBr)LaNb2O7 by an increase in the magnitude of the interdimer couplings J(eff)/J(4), with the (CuCl)LaM2O7 (M = Nb, Ta) compounds lying on different sides of the quantum critical point that separates the singlet and long-range-ordered magnetic ground states.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000308127600006	Publication Date	2012-08-29
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	6	Open Access
Notes				Approved	Most recent IF: 3.836; 2012 IF: 3.767
Call Number	UA @ lucian @ c:irua:101886			Serial	3526
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Author	Juchtmans, R.; Béché, A.; Abakumov, A.; Batuk, M.; Verbeeck, J.
Title	Using electron vortex beams to determine chirality of crystals in transmission electron microscopy			Type	A1 Journal article
Year	2015	Publication	Physical review : B : condensed matter and materials physics	Abbreviated Journal	Phys Rev B
Volume	91	Issue	91	Pages	094112
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We investigate electron vortex beams elastically scattered on chiral crystals. After deriving a general expression for the scattering amplitude of a vortex electron, we study its diffraction on point scatterers arranged on a helix. We derive a relation between the handedness of the helix and the topological charge of the electron vortex on one hand and the symmetry of the higher-order Laue zones in the diffraction pattern on the other for kinematically and dynamically scattered electrons. We then extend this to atoms arranged on a helix as found in crystals which belong to chiral space groups and propose a method to determine the handedness of such crystals by looking at the symmetry of the diffraction pattern. In contrast to alternative methods, our technique does not require multiple scattering, which makes it possible to also investigate extremely thin samples in which multiple scattering is suppressed. In order to verify the model, elastic scattering simulations are performed, and an experimental demonstration on Mn2Sb2O7 is given in which we find the sample to belong to the right-handed variant of its enantiomorphic pair. This demonstrates the usefulness of electron vortex beams to reveal the chirality of crystals in a transmission electron microscope and provides the required theoretical basis for further developments in this field.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000352017000002	Publication Date	2015-03-27
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	3.836	Times cited	54	Open Access
Notes	Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra1; esteem2jra2 ECASJO_;			Approved	Most recent IF: 3.836; 2015 IF: 3.736
Call Number	c:irua:125512 c:irua:125512			Serial	3825
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Author	Charkin, D.O.; Plokhikh, I.V.; Kazakov, S.M.; Kalmykov, S.N.; Akinfiev, V.S.; Gorbachev, A.V.; Batuk, M.; Abakumov, A.M.; Teterin, Y.A.; Maslakov, K.I.; Teterin, A.Y.; Ivanov, K.E.
Title	Synthesis and structural characterization of a novel Sillén – Aurivillius bismuth oxyhalide, PbBi3VO7.5Cl, and its derivatives			Type	A1 Journal article
Year	2018	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	75	Issue		Pages	27-33
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	A new Sillen – Aurivillius family of layered bismuth oxyhalides has been designed and successfully constructed on the basis of PbBiO2X(X = halogen) synthetic perites and g-form of Bi2VO5.5 solid elec- trolyte. This demonstrates, for the first time, the ability of the latter to serve as a building block in construction of mixed-layer structures. The parent compound PbBi3VO7.5-dCl (d = 0.05) has been investigated by powder XRD, TEM, XPS methods and magnetic susceptibility measurements. An unexpected but important condition for the formation of the mixed-layer structure is partial (ca. 5%) reduction of VV into VIV which probably suppresses competitive formation of apatite-like Pb – Bi vanadates. This reduction also stabilizes the g polymorphic form of Bi2VO5.5 not only in the intergrowth structure, but in Bi2V1-xMxO5.5-y (M – Nb, Sb) solid solutions.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000418566200005	Publication Date	2017-11-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	1	Open Access	Not_Open_Access
Notes	The work was partially supported by M.V. Lomonosov Moscow State University Program of Development and Russian Science Foundation under Grant No.14-13-00738. We also thank Dr. K.V. Zakharov (MSU) for the magnetic measurements of the PbBi3- VO7.5Cl sample.			Approved	Most recent IF: 1.811
Call Number	EMAT @ emat @c:irua:147239			Serial	4769
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Author	Abakumov, A.M.; Kalyuzhnaya, A.S.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.
Title	Compositionally induced phase transition in the Ca₂MnGa_1-xAl_xO₅ solid solutions: ordering of tetrahedral chains in brownmillerite structure			Type	A1 Journal article
Year	2005	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	7	Issue	7	Pages	801-811
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000230259500001	Publication Date	2005-04-30
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	38	Open Access
Notes	IAP V-1; RFBR 04-03-32785-a.			Approved	Most recent IF: 1.811; 2005 IF: 1.708
Call Number	UA @ lucian @ c:irua:54700			Serial	448
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Author	Hadermann, J.; Abakumov, A.M.; Nikolaev, I.V.; Antipov, E.V.; Van Tendeloo, G.
Title	Local structure of perovskite-based “Pb₂Fe₂O₅”			Type	A1 Journal article
Year	2008	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	10	Issue	4	Pages	382-389
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000256200200003	Publication Date	2008-01-20
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	29	Open Access
Notes				Approved	Most recent IF: 1.811; 2008 IF: 1.742
Call Number	UA @ lucian @ c:irua:69289			Serial	1832
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Author	Hervieu, M.; Damay, F.; Poienar, M.; Elkaim, E.; Rouquette, J.; Abakumov, A.M.; Van Tendeloo, G.; Maignan, A.; Martin, C.
Title	Nanostructures in LuFe₂O_4+\delta			Type	A1 Journal article
Year	2013	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	23	Issue		Pages	26-34
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	A LuFe2O4+delta sample, previously characterized by X-ray synchrotron and neutron diffraction, has been studied by electron microscopy techniques, in order to get a precise description of its micro- and nanostructures at room temperature. The X-ray synchrotron data vs. temperature show that the monoclinic distortion is associated with the charge ordering; this distortion results in elongated twinning domains, which enhance the complexity of the microstructural state at room temperature. The structural modulation associated with oxygen excess is observed in large domains inside a non modulated matrix, in contrast with the modulations associated with the charge ordering of the Fe2+ and Fe3+ species, which are mostly short-range. The investigation of the nature and density of defects in the sample shows that they are nano-scaled, preserving the regularity of the layer stacking mode, and limited to the formation of one- or two-units large stacking faults, associated with gliding mechanisms. Based on these observations, an original description of the LuFe2O4 ferrite structure, through puckered [LuO4](infinity) sandwiching [Fe-2](infinity) layers, is proposed. (C) 2013 Elsevier Masson SAS. All rights reserved.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000324156200005	Publication Date	2013-06-13
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	7	Open Access
Notes				Approved	Most recent IF: 1.811; 2013 IF: 1.679
Call Number	UA @ lucian @ c:irua:111196			Serial	2276
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Author	Lobanov, M.V.; Abakumov, A.M.; Sidorova, A.V.; Rozova, M.G.; D'yachenko, O.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.
Title	Synthesis and investigation of novel Mn-based oxyfluoride Sr₂Mn₂O_5-xF_1+x			Type	A1 Journal article
Year	2002	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	4	Issue		Pages	19-22
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000174141100004	Publication Date	2002-07-25
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	21	Open Access
Notes				Approved	Most recent IF: 1.811; 2002 IF: 1.667
Call Number	UA @ lucian @ c:irua:40346			Serial	3432
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Author	Abakumov, A.M.; Mironov, A.V.; Govorov, V.A.; Lobanov, M.V.; Rozova, M.G.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G.
Title	Synthesis and structural investigations on the new Sr_1.32Mn_0.83Cu_0.17O₃ compound			Type	A1 Journal article
Year	2003	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	5	Issue	8	Pages	1117-1125
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000185204900005	Publication Date	2003-06-30
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	8	Open Access
Notes				Approved	Most recent IF: 1.811; 2003 IF: 1.327
Call Number	UA @ lucian @ c:irua:54696			Serial	3436
Permanent link to this record



Author	Abakumov, A.M.; Rozova, M.G.; Alekseeva, A.M.; Kovba, M.L.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G.
Title	Synthesis and structure of Sr₂MnGaO_5+\delta brownmillerites with variable oxygen content			Type	A1 Journal article
Year	2003	Publication	Solid state sciences	Abbreviated Journal	Solid State Sci
Volume	5	Issue	6	Pages	871-882
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000184765000005	Publication Date	2003-06-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1293-2558;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.811	Times cited	12	Open Access
Notes				Approved	Most recent IF: 1.811; 2003 IF: 1.327
Call Number	UA @ lucian @ c:irua:54698			Serial	3445
Permanent link to this record



Author	Tytgat, T.; Hauchecorne, B.; Abakumov, A.M.; Smits, M.; Verbruggen, S.W.; Lenaerts, S.
Title	Photocatalytic process optimisation for ethylene oxidation			Type	A1 Journal article
Year	2012	Publication	Chemical engineering journal	Abbreviated Journal	Chem Eng J
Volume	209	Issue		Pages	494-500
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract	When studying photocatalysis it is important to consider, beside the chemical approach, the engineering part related to process optimisation. To achieve this a fixed bed photocatalytic set-up consisting of different catalyst placings, in order to vary catalyst distribution, is studied. The use of a fixed quantity of catalyst placed packed or randomly distributed in the reactor, results in an almost double degradation for the distributed catalyst. Applying this knowledge leads to an improved performance with limited use of catalyst. A reactor only half filled with catalyst leads to higher degradation performance compared to a completely filled reactor. Taking into account this simple process optimisation by better distributing the catalyst a more sustainable photocatalytic air purification process is achieved. (C) 2012 Elsevier B.V. All rights reserved.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Lausanne	Editor
Language		Wos	000311190500058	Publication Date	2012-08-22
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1385-8947;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	6.216	Times cited	12	Open Access
Notes	; We are grateful for the delivered photocatalyst by Evonik as well as for the PhD grant (T. Tytgat) given by the Institute of Innovation by Science and Technology in Flanders (IWT). ;			Approved	Most recent IF: 6.216; 2012 IF: 3.473
Call Number	UA @ lucian @ c:irua:105185			Serial	2609
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Author	Batuk, D.; Batuk, M.; Tsirlin, A.A.; Hadermann, J.; Abakumov, A.M.
Title	Trapping of Oxygen Vacancies at Crystallographic Shear Planes in Acceptor-Doped Pb-Based Ferroelectrics			Type	A1 Journal article
Year	2015	Publication	Angewandte Chemie: international edition in English	Abbreviated Journal	Angew Chem Int Edit
Volume	54	Issue	54	Pages	14787-14790
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The defect chemistry of the ferroelectric material PbTiO3 after doping with Fe(III) acceptor ions is reported. Using advanced transmission electron microscopy and powder X-ray and neutron diffraction, we demonstrate that even at concentrations as low as circa 1.7% (material composition approximately ABO2.95), the oxygen vacancies are trapped into extended planar defects, specifically crystallographic shear planes. We investigate the evolution of these defects upon doping and unravel their detailed atomic structure using the formalism of superspace crystallography, thus unveiling their role in nonstoichiometry in the Pb-based perovskites.
Address	Chemistry Department, Moscow State University, 119991, Moscow (Russia). artem.abakumov@uantwerpen.be
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language	English	Wos	000367723400031	Publication Date	2015-10-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1433-7851	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	11.994	Times cited	3	Open Access
Notes	A.M.A. is grateful to the Russian Science Foundation (grant 14-13-00680). AT was funded by the Mobilitas grant MTT77 of the ESF and by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation.			Approved	Most recent IF: 11.994; 2015 IF: 11.261
Call Number	c:irua:131104			Serial	4080
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Author	Kirsanova, M.A.; Olenev, A.V.; Abakumov, A.M.; Bykov, M.A.; Shevelkov, A.V.
Title	Extension of the clathrate family : the type X clathrate Ge₇₉P₂₉S₁₈Te₆			Type	A1 Journal article
Year	2011	Publication	Angewandte Chemie: international edition in English	Abbreviated Journal	Angew Chem Int Edit
Volume	50	Issue	10	Pages	2371-2374
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow).
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000288036300033	Publication Date	2011-01-31
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1433-7851;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	11.994	Times cited	23	Open Access
Notes				Approved	Most recent IF: 11.994; 2011 IF: 13.455
Call Number	UA @ lucian @ c:irua:88793			Serial	1158
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Author	Ovsyannikov, S.V.; Abakumov, A.M.; Tsirlin, A.A.; Schnelle, W.; Egoavil, R.; Verbeeck, J.; Van Tendeloo, G.; Glazyrin, K.V.; Hanfland, M.; Dubrovinsky, L.
Title	Perovskite-like Mn₂O₃ : a path to new manganites			Type	A1 Journal article
Year	2013	Publication	Angewandte Chemie	Abbreviated Journal	Angew Chem Int Edit
Volume	52	Issue	5	Pages	1494-1498
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Korund-artiges ε-Mn2O3 und Perowskit-artiges ζ-Mn2O3, zwei neue Phasen von Mn2O3, wurden unter hohen Drücken bei hohen Temperaturen synthetisiert. Die Manganatome können vollständig die A- und B-Positionen der Perowskitstruktur besetzen. ζ-Mn2O3 (siehe Bild, A-Positionsordnung) enthält Mn in den drei Oxidationsstufen +II, +III und +IV.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000313913300027	Publication Date	2012-12-22
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1433-7851;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	11.994	Times cited	84	Open Access
Notes	This work was supported by the DFG (project OV-110/1-1), Alexander von Humboldt foundation, European Union Council (FP7)-Grant no. 246102 IFOX, European Research Council (FP7)-ERC Starting Grant no. 278510 VORTEX and ERC Grant no. 246791-COUNTATOMS, and Hercules fund from the Flemish Government. ECASJO_;			Approved	Most recent IF: 11.994; 2013 IF: 11.336
Call Number	UA @ lucian @ c:irua:108765UA @ admin @ c:irua:108765			Serial	2573
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Author	Gardner, G.P.; Go, Y.B.; Robinson, D.M.; Smith, P.F.; Hadermann, J.; Abakumov, A.; Greenblatt, M.; Dismukes, G.C.
Title	Structural requirements in lithium cobalt oxides for the catalytic oxidation of water			Type	A1 Journal article
Year	2012	Publication	Angewandte Chemie: international edition in English	Abbreviated Journal	Angew Chem Int Edit
Volume	51	Issue	7	Pages	1616-1619
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000299946400020	Publication Date	2012-01-11
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1433-7851;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	11.994	Times cited	119	Open Access
Notes				Approved	Most recent IF: 11.994; 2012 IF: 13.734
Call Number	UA @ lucian @ c:irua:99173			Serial	3258
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Author	Abakumov, A.M.; Hadermann, J.; Bals, S.; Nikolaev, I.V.; Antipov, E.V.; Van Tendeloo, G.
Title	Crystallographic shear structures as a route to anion-deficient perovskites			Type	A1 Journal article
Year	2006	Publication	Angewandte Chemie: international edition in English	Abbreviated Journal	Angew Chem Int Edit
Volume	45	Issue	40	Pages	6697-6700
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000241474500022	Publication Date	2006-09-13
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1433-7851;1521-3773;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	11.994	Times cited	62	Open Access
Notes				Approved	Most recent IF: 11.994; 2006 IF: 10.232
Call Number	UA @ lucian @ c:irua:61689			Serial	589
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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
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
Volume	2019	Issue	2019	Pages	4365-4372
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
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.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000484135500001	Publication Date	2019-08-07
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1434-1948	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	2.444	Times cited		Open Access
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
Call Number	UA @ admin @ c:irua:162857			Serial	5403
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Author	Isaeva, A.A.; Makarevich, O.N.; Kutznetsov, A.N.; Doert, T.; Abakumov, A.M.; Van Tendeloo, G.
Title	Mixed tellurides Ni_3-xGaTe₂ (0\leq x\leq0.65): crystal and electronic structures, properties, and nickel deficiency effects on vacancy ordering			Type	A1 Journal article
Year	2010	Publication	European journal of inorganic chemistry	Abbreviated Journal	Eur J Inorg Chem
Volume		Issue	9	Pages	1395-1404
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The Ni3-xGaTe2 series of compounds (0 x 0.65) was synthesized by a high-temperature ceramic technique at 750 °C. Crystal structures of three compounds in the series were determined by X-ray powder diffraction: Ni2.98(1)GaTe2 (RI = 0.042, Rp = 0.023, Rwp = 0.035), Ni2.79(1)GaTe2 (RI = 0.053, Rp = 0.028, Rwp = 0.039), Ni2.58(1)GaTe2 (RI = 0.081, Rp = 0.037, Rwp = 0.056); the structures were verified by electron diffraction and, for the former compound, high-resolution electron microscopy. The compounds crystallize in a hexagonal lattice with P63/mmc, and the structures can be regarded as a hexagonal close-packed array with a -Ga-Te-Te- stacking sequence. The octahedral and trigonal bipyramidal voids in the hcp structure are selectively filled with Ni atoms to form one entirely occupied and two partially occupied sites, thus allowing variations in the nickel content in the series of compounds Ni3-xGaTe2 (0 x 0.65). A superstructure with asup = 2asub (P63/mmc) has been identified for Ni3-xGaTe2 (0.5 x 0.65) by electron diffraction. Real-space, high-resolution images confirm an ordering of Ni atoms and vacancies inthe ab plane. Quantum-chemical calculations performed forNi3-xGaTe2 (x = 0, 0.25, 0.75, 1) suggest anisotropic metallic conductivity and Pauli paramagnetic behavior that are experimentally confirmed for Ni3GaTe2.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000276370300009	Publication Date	2010-02-12
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1434-1948;1099-0682;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	2.444	Times cited	8	Open Access
Notes				Approved	Most recent IF: 2.444; 2010 IF: 2.910
Call Number	UA @ lucian @ c:irua:82266			Serial	2090
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Author	Mefford, J.T.; Kurilovich, A.A.; Saunders, J.; Hardin, W.G.; Abakumov, A.M.; Forslund, R.P.; Bonnefont, A.; Dai, S.; Johnston, K.P.; Stevenson, K.J.
Title	Decoupling the roles of carbon and metal oxides on the electrocatalytic reduction of oxygen on La_1-xSr_xCoO_3-\delta perovskite composite electrodes			Type	A1 Journal article
Year	2019	Publication	Physical chemistry, chemical physics	Abbreviated Journal	Phys Chem Chem Phys
Volume	21	Issue	6	Pages	3327-3338
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Perovskite oxides are active room-temperature bifunctional oxygen electrocatalysts in alkaline media, capable of performing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with lower combined overpotentials relative to their precious metal counterparts. However, their semiconducting nature necessitates the use of activated carbons as conductive supports to generate applicably relevant current densities. In efforts to advance the performance and theory of oxide electrocatalysts, the chemical and physical properties of the oxide material often take precedence over contributions from the conductive additive. In this work, we find that carbon plays an important synergistic role in improving the performance of La1-xSrxCoO3- (0 x 1) electrocatalysts through the activation of O-2 and spillover of radical oxygen intermediates, HO2- and O-2(-), which is further reduced through chemical decomposition of HO2- on the perovskite surface. Through a combination of thin-film rotating disk electrochemical characterization of the hydrogen peroxide intermediate reactions (hydrogen peroxide reduction reaction (HPRR), hydrogen peroxide oxidation reaction (HPOR)) and oxygen reduction reaction (ORR), surface chemical analysis, HR-TEM, and microkinetic modeling on La1-xSrxCoO3- (0 x 1)/carbon (with nitrogen and non-nitrogen doped carbons) composite electrocatalysts, we deconvolute the mechanistic aspects and contributions to reactivity of the oxide and carbon support.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000459584900049	Publication Date	2019-01-18
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1463-9076; 1463-9084	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	4.123	Times cited	5	Open Access	OpenAccess
Notes	; Financial support for this work was provided by the R. A. Welch Foundation (grants F-1529 and F-1319). S. D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. ;			Approved	Most recent IF: 4.123
Call Number	UA @ admin @ c:irua:158625			Serial	5244
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Author	Hadermann, J.; Van Tendeloo, G.; Abakumov, A.M.; Pavlyuk, B.P.; Rozova, M.G.; Antipov, E.V.
Title	Structural transformation in fluorinated LaACuGaO₅ (A=Ca, Sr) brownmillerites			Type	A1 Journal article
Year	2000	Publication	International journal of inorganic materials	Abbreviated Journal	Int J Inorg Mater
Volume	2	Issue	6	Pages	493-502
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Amsterdam	Editor
Language		Wos	000165985400005	Publication Date	2002-07-25
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1466-6049;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor		Times cited	13	Open Access
Notes				Approved	Most recent IF: NA
Call Number	UA @ lucian @ c:irua:36043			Serial	3265
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Author	Pearce, P.E.; Perez, A.J.; Rousse, G.; Saubanère, M.; Batuk, D.; Foix, D.; McCalla, E.; Abakumov, A.M.; Van Tendeloo, G.; Doublet, M.-L.; Tarascon, J.-M.
Title	Evidence for anionic redox activity in a tridimensional-ordered Li-rich positive electrode β-Li2IrO3			Type	A1 Journal article
Year	2017	Publication	Nature materials	Abbreviated Journal	Nat Mater
Volume	16	Issue	5	Pages	580-586
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Lithium-ion battery cathode materials have relied on cationic redox reactions until the recent discovery of anionic redox activity in Li-rich layered compounds which enables capacities as high as 300 mAh g(-1). In the quest for new high-capacity electrodes with anionic redox, a still unanswered question was remaining regarding the importance of the structural dimensionality. The present manuscript provides an answer. We herein report on a beta-Li2IrO3 phase which, in spite of having the Ir arranged in a tridimensional (3D) framework instead of the typical two-dimensional (2D) layers seen in other Li-rich oxides, can reversibly exchange 2.5 e(-) per Ir, the highest value ever reported for any insertion reaction involving d-metals. We show that such a large activity results from joint reversible cationic (Mn+) and anionic (O-2)(n-) redox processes, the latter being visualized via complementary transmission electron microscopy and neutron diffraction experiments, and confirmed by density functional theory calculations. Moreover, beta-Li2IrO3 presents a good cycling behaviour while showing neither cationic migration nor shearing of atomic layers as seen in 2D-layered Li-rich materials. Remarkably, the anionic redox process occurs jointly with the oxidation of Ir4+ at potentials as low as 3.4 V versus Li+/Li-0, as equivalently observed in the layered alpha-Li2IrO3 polymorph. Theoretical calculations elucidate the electrochemical similarities and differences of the 3D versus 2D polymorphs in terms of structural, electronic and mechanical descriptors. Our findings free the structural dimensionality constraint and broaden the possibilities in designing high-energy-density electrodes for the next generation of Li-ion batteries.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000400004200018	Publication Date	2017-02-27
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1476-1122	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	39.737	Times cited		Open Access	Not_Open_Access
Notes	The authors thank Q. Jacquet for fruitful discussions and V. Pomjakushin for his valuable help in neutron diffraction experiments. This work is based on experiments performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institute, Villigen, Switzerland. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the US Department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. E.M. acknowledges financial support from the Fonds de Recherche du Quebec-Nature et Technologies.			Approved	Most recent IF: 39.737
Call Number	EMAT @ emat @c:irua:147502			Serial	4773
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Author	Erni, R.; Abakumov, A.M.; Rossell, M.D.; Batuk, D.; Tsirlin, A.A.; Nénert, G.; Van Tendeloo, G.
Title	Nanoscale phase separation in perovskites revisited			Type	L1 Letter to the editor
Year	2014	Publication	Nature materials	Abbreviated Journal	Nat Mater
Volume	13	Issue	3	Pages	216-217
Keywords	L1 Letter to the editor; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	London	Editor
Language		Wos	000331945200002	Publication Date	2014-02-20
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1476-1122;1476-4660;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	39.737	Times cited	5	Open Access
Notes				Approved	Most recent IF: 39.737; 2014 IF: 36.503
Call Number	UA @ lucian @ c:irua:114579			Serial	2270
Permanent link to this record



Author	Sathiya, M.; Abakumov, A.M.; Foix, D.; Rousse, G.; Ramesha, K.; Saubanère, M.; Doublet, M. .; Vezin, H.; Laisa, C.P.; Prakash, A.S.; Gonbeau, D.; Van Tendeloo, G.; Tarascon, J.M.
Title	Origin of voltage decay in high-capacity layered oxide electrodes			Type	A1 Journal article
Year	2015	Publication	Nature materials	Abbreviated Journal	Nat Mater
Volume	14	Issue	14	Pages	230-238
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Although Li-rich layered oxides (Li1+xNiyCozMn1−x−y−zO2 > 250 mAh g−1) are attractive electrode materials providing energy densities more than 15% higher than todays commercial Li-ion cells, they suffer from voltage decay on cycling. To elucidate the origin of this phenomenon, we employ chemical substitution in structurally related Li2RuO3 compounds. Li-rich layered Li2Ru1−yTiyO3 phases with capacities of ~240 mAh g−1 exhibit the characteristic voltage decay on cycling. A combination of transmission electron microscopy and X-ray photoelectron spectroscopy studies reveals that the migration of cations between metal layers and Li layers is an intrinsic feature of the chargedischarge process that increases the trapping of metal ions in interstitial tetrahedral sites. A correlation between these trapped ions and the voltage decay is established by expanding the study to both Li2Ru1−ySnyO3 and Li2RuO3; the slowest decay occurs for the cations with the largest ionic radii. This effect is robust, and the finding provides insights into new chemistry to be explored for developing high-capacity layered electrodes that evade voltage decay.
Address
Corporate Author				Thesis
Publisher		Place of Publication	London	Editor
Language		Wos	000348600200024	Publication Date	2014-12-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1476-1122;1476-4660;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	39.737	Times cited	395	Open Access
Notes	246791 Countatoms; 312483 Esteem2; esteem2_ta			Approved	Most recent IF: 39.737; 2015 IF: 36.503
Call Number	c:irua:132555 c:irua:132555			Serial	2528
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Author	Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J.
Title	A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction			Type	A1 Journal article
Year	2016	Publication	Journal of the Chemical Society : Dalton transactions	Abbreviated Journal	Dalton T
Volume	45	Issue	45	Pages	973-979
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations.
Address	Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language	English	Wos	000367614700018	Publication Date	2015-11-23
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1477-9226	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	4.029	Times cited	6	Open Access
Notes	We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2			Approved	Most recent IF: 4.029
Call Number	c:irua:130408 c:irua:130408			Serial	3998
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Author	Tyablikov, O.A.; Batuk, D.; Tsirlin, A.A.; Batuk, M.; Verchenko, V.Y.; Filimonov, D.S.; Pokholok, K.V.; Sheptyakov, D.V.; Rozova, M.G.; Hadermann, J.; Antipov, E.V.; Abakumov, A.M.;
Title	{110}-Layered B-cation ordering in the anion-deficient perovskite Pb_2.4Ba_2.6Fe₂Sc₂TiO₁₃ with the crystallographic shear structure			Type	A1 Journal article
Year	2015	Publication	Journal of the Chemical Society : Dalton transactions	Abbreviated Journal	Dalton T
Volume	44	Issue	44	Pages	10753-10762
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	A novel anion-deficient perovskite-based compound, Pb2.4Ba2.6Fe2Sc2TiO13, was synthesized via the citrate-based route. This compound is an n = 5 member of the A(n)B(n)O(3n-2) homologous series with unit-cell parameters related to the perovskite subcell a(p) approximate to 4.0 angstrom as a(p)root 2 x a(p) x 5a(p)root 2. The crystal structure of Pb2.4Ba2.6Fe2Sc2TiO13 consists of quasi-2D perovskite blocks with a thickness of three octahedral layers separated by the 1/2[110]((1) over bar 01)(p) crystallographic shear (CS) planes, which are parallel to the {110} plane of the perovskite subcell. The CS planes transform the corner-sharing octahedra into chains of edge-sharing distorted tetragonal pyramids. Using a combination of neutron powder diffraction, Fe-57 Mossbauer spectroscopy and atomic resolution electron energy-loss spectroscopy we demonstrate that the B-cations in Pb2.4Ba2.6Fe2Sc2TiO13 are ordered along the {110} perovskite layers with Fe3+ in distorted tetragonal pyramids along the CS planes, Ti4+ preferentially in the central octahedra of the perovskite blocks and Sc3+ in the outer octahedra of the perovskite blocks. Magnetic susceptibility and Mossbauer spectroscopy indicate a broadened magnetic transition around T-N similar to 45 K and the onset of local magnetic fields at low temperatures. The magnetic order is probably reminiscent of that in other A(n)B(n)O(3n-2) homologues, where G-type AFM order within the perovskite blocks has been observed.
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Corporate Author				Thesis
Publisher		Place of Publication	London	Editor
Language		Wos	000355701000026	Publication Date	2015-01-26
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1477-9226;1477-9234;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	4.029	Times cited	1	Open Access
Notes				Approved	Most recent IF: 4.029; 2015 IF: 4.197
Call Number	c:irua:127001			Serial	22
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