NANOlab Center of Excellence literature database -- Query Results

<< 1 2 3 4 5 6 7 8 >>

Details

Records
Author	Zaikina, J.V.; Batuk, M.; Abakumov, A.M.; Navrotsky, A.; Kauziarich, S.M.
Title	Facile synthesis of Ba_1-xK_xFe₂As₂ superconductors via hydride route			Type	A1 Journal article
Year	2014	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	136	Issue	48	Pages	16932-16939
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We have developed a fast, easy, and scalable synthesis method for Ba1xKxFe2As2 (0 ≤ x ≤ 1) superconductors using hydrides BaH2 and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba1xKxFe2As2 obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature Tc upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000345883900040	Publication Date	2014-11-11
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863;1520-5126;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	13	Open Access
Notes				Approved	Most recent IF: 13.858; 2014 IF: 12.113
Call Number	UA @ lucian @ c:irua:121331			Serial	1169
Permanent link to this record



Author	Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V.
Title	Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides			Type	A1 Journal article
Year	2011	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	133	Issue	4	Pages	692-694
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000287295300015	Publication Date	2010-12-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863;1520-5126;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	28	Open Access
Notes				Approved	Most recent IF: 13.858; 2011 IF: 9.907
Call Number	UA @ lucian @ c:irua:88820			Serial	1236
Permanent link to this record



Author	Li, M.R.; Adem, U.; McMitchell, S.R.C.; Xu, Z.; Thomas, C.I.; Warren, J.E.; Giap, D.V.; Niu, H.; Wan, X.; Palgrave, R.G.; Schiffmann, F.; Cora, F.; Slater, B.; Burnett, T.L.; Cain, M.G.; Abakumov, A.M.; Van Tendeloo, G.; Thomas, M.F.; Rosseinsky, M.J.; Claridge, J.B.;
Title	A polar corundum oxide displaying weak ferromagnetism at room temperature			Type	A1 Journal article
Year	2012	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	134	Issue	8	Pages	3737-3747
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Combining long-range magnetic order with polarity in the same structure is a prerequisite for the design of (magnetoelectric) multiferroic materials. There are now several demonstrated strategies to achieve this goal, but retaining magnetic order above room temperature remains a difficult target. Iron oxides in the +3 oxidation state have high magnetic ordering temperatures due to the size of the coupled moments. Here we prepare and characterize ScFeO3 (SFO), which under pressure and in strain-stabilized thin films adopts a polar variant of the corundum structure, one of the archetypal binary oxide structures. Polar corundum ScFeO3 has a weak ferromagnetic ground state below 356 K-this is in contrast to the purely antiferromagnetic ground state adopted by the well-studied ferroelectric BiFeO3.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000301161600027	Publication Date	2012-01-23
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863;1520-5126;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	48	Open Access
Notes				Approved	Most recent IF: 13.858; 2012 IF: 10.677
Call Number	UA @ lucian @ c:irua:97200			Serial	2658
Permanent link to this record



Author	Subban, C.V.; Ati, M.; Rousse, G.; Abakumov, A.M.; Van Tendeloo, G.; Janot, R.; Tarascon, J.-M.
Title	Preparation, structure, and electrochemistry of layered polyanionic hydroxysulfates : LiMSO₄OH (M = Fe, Co, Mn) electrodes for Li-Ion batteries			Type	A1 Journal article
Year	2013	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	135	Issue	9	Pages	3653-3661
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The Li-ion rechargeable battery, due to its high energy density, has driven remarkable advances in portable electronics. Moving toward more sustainable electrodes could make this technology even more attractive to large-volume applications. We present here a new family of 3d-metal hydroxysulfates of general formula LiMSO4OH (M = Fe, Co, and Mn) among which (i) LiFeSO4OH reversibly releases 0.7 Li+ at an average potential of 3.6 V vs Li+/Li-0, slightly higher than the potential of currently lauded LiFePO4 (3.45 V) electrode material, and (ii) LiCoSO4OH shows a redox activity at 4.7 V vs Li+/Li-0. Besides, these compounds can be easily made at temperatures near 200 degrees C via a synthesis process that enlists a new intermediate phase of composition M-3(SO4)(2)(OH)(2) (M = Fe, Co, Mn, and Ni), related to the mineral caminite. Structurally, we found that LiFeSO4OH is a layered phase unlike the previously reported 3.2 V tavorite LiFeSO4OH. This work should provide an impetus to experimentalists for designing better electrolytes to fully tap the capacity of high-voltage Co-based hydroxysulfates, and to theorists for providing a means to predict the electrochemical redox activity of two polymorphs.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000315936700056	Publication Date	2013-02-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863;1520-5126;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	53	Open Access
Notes				Approved	Most recent IF: 13.858; 2013 IF: 11.444
Call Number	UA @ lucian @ c:irua:108283			Serial	2708
Permanent link to this record



Author	Hadermann, J.; Abakumov, A.M.; Adkin, J.J.; Hayward, M.A.
Title	Topotactic reduction as a route to new close-packed anion deficient perovskites: structure and magnetism of 4H-BaMnO_2+x			Type	A1 Journal article
Year	2009	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	131	Issue	30	Pages	10598-10604
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The anion-deficient perovskite 4H-BaMnO2+x has been obtained by a topotactic reduction, with LiH, of the hexagonal perovskite 4H-BaMnO3−x. The crystal structure of 4H-BaMnO2+x was solved using electron diffraction and X-ray powder diffraction and further refined using neutron powder diffraction (S.G. Pnma, a = 10.375(2) Å, b = 9.466(2) Å, c = 11.276(3) Å, at 373 K). The orthorhombic superstructure arises from the ordering of oxygen vacancies within a 4H (chch) stacking of close packed c-type BaO2.5 and h-type BaO1.5 layers. The ordering of the oxygen vacancies transforms the Mn2O9 units of face-sharing MnO6 octahedra into Mn2O7 (two corner-sharing tetrahedra) and Mn2O6 (two edge-sharing tetrahedra) groups. The Mn2O7 and Mn2O6 groups are linked by corner-sharing into a three-dimensional framework. The structures of the BaO2.5 and BaO1.5 layers are different from those observed previously in anion-deficient perovskites providing a new type of order pattern of oxygen atoms and vacancies in close packed structures. Magnetization measurements and neutron diffraction data reveal 4H-BaMnO2+x adopts an antiferromagnetically ordered state below TN ≈ 350 K.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000268644400056	Publication Date	2009-07-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863;1520-5126;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	25	Open Access
Notes				Approved	Most recent IF: 13.858; 2009 IF: 8.580
Call Number	UA @ lucian @ c:irua:77928			Serial	3681
Permanent link to this record



Author	Mikita, R.; Aharen, T.; Yamamoto, T.; Takeiri, F.; Ya, T.; Yoshimune, W.; Fujita, K.; Yoshida, S.; Tanaka, K.; Batuk, D.; Abakumov, A.M.; Brown, C.M.; Kobayashi, Y.; Kageyama, H.;
Title	Topochemical nitridation with anion vacancy -assisted N^3-/O^2- exchange			Type	A1 Journal article
Year	2016	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	138	Issue	138	Pages	3211-3217
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	We present how the introduction of anion vacancies in oxyhydrides enables a route to access new oxynitrides, by conducting ammonolysis of perovskite oxyhydride EuTiO3-xHx (x similar to 0.18). At 400 degrees C, similar to our studies on BaTiO3-xHx, hydride lability enables a low temperature direct ammonolysis of EUTi3.82+O-2.82/H-0.18, leading to the N3-/H--exchanged product EuTi4+O2.82No0.12 square 0.06 center dot When the ammonolysis temperature was increased up to 800 degrees C, we observed a further nitridation involving N3-/O2- exchange, yielding a fully oxidized Eu3+Ti4+O2N with the GdFeO3-type distortion (Pnma) as a metastable phase, instead of pyrochlore structure. Interestingly, the same reactions using the oxide EuTiO3 proceeded through a 1:1 exchange of N3- with O-2 only above 600 degrees C and resulted in incomplete nitridation to EuTi02.25N0.75, indicating that anion vacancies created during the initial nitridation process of EuTiO2.82H0.18 play a crucial role in promoting anion (N3-/O2-) exchange at high temperatures. Hence, by using (hydride-induced) anion-deficient precursors, we should be able to expand the accessible anion composition of perovskite oxynitrides.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000371945800055	Publication Date	2016-02-08
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	28	Open Access
Notes				Approved	Most recent IF: 13.858
Call Number	UA @ lucian @ c:irua:133156			Serial	4266
Permanent link to this record



Author	Kuno, Y.; Tassel, C.; Fujita, K.; Batuk, D.; Abakumov, A.M.; Shitara, K.; Kuwabara, A.; Moriwake, H.; Watabe, D.; Ritter, C.; Brown, C.M.; Yamamoto, T.; Takeiri, F.; Abe, R.; Kobayashi, Y.; Tanaka, K.; Kageyama, H.
Title	ZnTaO2N: Stabilized High-Temperature LiNbO3-type Structure			Type	A1 Journal article
Year	2016	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	138	Issue	138	Pages	15950-15955
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	By using a high-pressure reaction, we prepared a new oxynitride ZnTaO2N that crystallizes in a centrosymmetric (R (3) over barc) high-temperature LiNbO3-type structure (HTLN-type). The stabilization of the HTLN-type structure down to low temperatures (at least 20 K) makes it possible to investigate not only the stability of this phase, but also the phase transition to a noncentrosymmetric (R3c) LiNbO3-type structure (LN-type) which is yet to be clarified. Synchrotron and neutron diffraction studies in combination with transmission electron microscopy show that Zn is located at a disordered 12c site instead of 6a, implying an order disorder mechanism of the phase transition. It is found that the dosed d-shell of Zn2+, as well as the high-valent Ta5+ ion, is responsible for the stabilization of the HTLN-type structure, affording a novel quasitriangular ZnO2N coordination. Interestingly, only 3% Zn substitution for MnTaO2N induces a phase transition from LN- to HTLN-type structure, implying the proximity in energy between the two structural types, which is supported by the first-principles calculations.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000389962800032	Publication Date	2016-11-18
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	13	Open Access
Notes				Approved	Most recent IF: 13.858
Call Number	UA @ lucian @ c:irua:140298			Serial	4452
Permanent link to this record



Author	Niu, H.; Pitcher, M.J.; Corkett, A.J.; Ling, S.; Mandal, P.; Zanella, M.; Dawson, K.; Stamenov, P.; Batuk, D.; Abakumov, A.M.; Bull, C.L.; Smith, R.I.; Murray, C.A.; Day, S.J.; Slater, B.; Cora, F.; Claridge, J.B.; Rosseinsky, M.J.
Title	Room Temperature Magnetically Ordered Polar Corundum GaFeO3 Displaying Magnetoelectric Coupling			Type	A1 Journal article
Year	2017	Publication	Journal of the American Chemical Society	Abbreviated Journal	J Am Chem Soc
Volume	139	Issue	4	Pages	1520-1531
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The polar corundum structure type offers a route to new room temperature multiferroic materials, as the partial LiNbO3-type cation ordering that breaks inversion symmetry may be combined with long-range magnetic ordering of high spin d(5) cations above room temperature in the AFeO(3) system. We report the synthesis of a polar corundum GaFeO3 by a high-pressure, high-temperature route and demonstrate that its polarity arises from partial LiNbO3 -type cation ordering by complementary use of neutron, X-ray, and electron diffraction methods. In situ neutron diffraction shows that the polar corundum forms directly from AlFeO3-type GaFeO3 under the synthesis conditions. The A(3+)/Fe3+ cations are shown to be more ordered in polar corundum GaFeO3 than in isostructural ScFeO3. This is explained by DFT calculations which indicate that the extent of ordering is dependent on the configurational entropy available to each system at the very different synthesis temperatures required to form their corundum structures. Polar corundum GaFeO3 exhibits weak ferromagnetism at room temperature that arises from its Fe2O3-like magnetic ordering, which persists to a temperature of 408 K. We demonstrate that the polarity and magnetization are coupled in this system with a measured linear magnetoelectric coupling coefficient of 0.057 ps/m. Such coupling is a prerequisite for potential applications of polar corundum materials in multiferroic/magnetoelectric devices.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000393355600034	Publication Date	2016-12-25
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0002-7863	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.858	Times cited	12	Open Access	OpenAccess
Notes	This work was funded by the EPSRC under EP/N004884. We thank the STFC for provision of beam time at ISIS and Diamond Light Source. We thank the Materials Chemistry Consortium (EPSRC, EP/L000202) for access to computer time on the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk). A.M.A. is grateful to the Russian Science Foundation (Grant 14-13-00680) for financial support. MJ.R is a Royal Society Research Professor. We wish to thank Dr. Ming Li (University of Nottingham, UK) for helpful discussion and advice. Original data is available at the University of Liverpool's DataCat repository at DOI: 10.17638/datacat.liverpool.ac.uk/235. The supporting crystallographic information file may also be obtained from FIZ Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany (e-mail: crysdata@fiz-karlsruhe.de), on quoting the deposition number CSD-432419.			Approved	Most recent IF: 13.858
Call Number	EMAT @ emat @c:irua:147507			Serial	4777
Permanent link to this record



Author	Rossell, M.D.; Abakumov, A.M.; Ramasse, Q.M.; Erni, R.
Title	Direct evidence of stacking disorder in the mixed ionic-electronic conductor Sr₄Fe₆O_12+\delta			Type	A1 Journal article
Year	2013	Publication	ACS nano	Abbreviated Journal	Acs Nano
Volume	7	Issue	4	Pages	3078-3085
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Determining the structure-to-property relationship of materials becomes particularly challenging when the material under investigation is dominated by defects and structural disorder. Knowledge on the exact atomic arrangement at the defective structure is required to understand its influence on the functional properties. However, standard diffraction techniques deliver structural information that is averaged over many unit cells. In particular, information about defects and order-disorder phenomena is contained in the coherent diffuse scattering intensity which often is difficult to uniquely interpret. Thus, the examination of the local disorder in materials requires a direct method to study their structure on the atomic level with chemical sensitivity. Using aberration-corrected scanning transmission electron microscopy in combination with atomic-resolution electron energy-loss spectroscopy, we show that the controversial structural arrangement of the Fe2O2+delta layers in the mixed ionic-electronic conducting Sr4Fe6O12+delta perovskite can be unambiguously resolved. Our results provide direct experimental evidence for the presence of a nanomixture of “ordered” and “disordered” domains in an epitaxial Sr4Fe6O12+delta thin film. The most favorable arrangement is the disordered structure and is interpreted as a randomly occurring but well-defined local shift of the Fe-O chains in the Fe2O2+delta layers. By analyzing the electron energy-loss near-edge structure of the different building blocks in the Sr4Fe6O12+delta unit cell we find that the mobile holes in this mixed ionic-electronic conducting oxide are highly localized in the Fe2O2+delta layers, which are responsible for the oxide-ion conductivity. A possible link between disorder and oxygen-ion transport along the Fe2O2+delta layers is proposed by arguing that the disorder can effectively break the oxygen diffusion pathways.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000318143300021	Publication Date	2013-03-04
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1936-0851;1936-086X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.942	Times cited	4	Open Access
Notes				Approved	Most recent IF: 13.942; 2013 IF: 12.033
Call Number	UA @ lucian @ c:irua:108476			Serial	713
Permanent link to this record



Author	Altantzis, T.; Coutino-Gonzalez, E.; Baekelant, W.; Martinez, G.T.; Abakumov, A.M.; Van Tendeloo, G.; Roeffaers, M.B.J.; Bals, S.; Hofkens, J.
Title	Direct Observation of Luminescent Silver Clusters Confined in Faujasite Zeolites			Type	A1 Journal article
Year	2016	Publication	ACS nano	Abbreviated Journal	Acs Nano
Volume	10	Issue	10	Pages	7604-7611
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	One of the ultimate goals in the study of metal clusters is the correlation between the atomic-scale organization and their physicochemical properties. However, direct observation of the atomic organization of such minuscule metal clusters is heavily hindered by radiation damage imposed by the different characterization techniques. We present direct evidence of the structural arrangement, at an atomic level, of luminescent silver species stabilized in faujasite (FAU) zeolites using aberration-corrected scanning transmission electron microscopy. Two different silver clusters were identified in Ag-FAU zeolites, a trinuclear silver species associated with green emission and a tetranuclear silver species related to yellow emission. By combining direct imaging with complementary information obtained from X-ray powder diffraction and Rietveld analysis, we were able to elucidate the main differences at an atomic scale between luminescent (heat-treated) and nonluminescent (cation-exchanged) Ag-FAU zeolites. It is expected that such insights will trigger the directed synthesis of functional metal nanocluster-zeolite composites with tailored luminescent properties.
Address	RIES, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language	English	Wos	000381959100043	Publication Date	2016-07-08
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1936-0851	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	13.942	Times cited	57	Open Access	OpenAccess
Notes	The authors gratefully acknowledge financial support from the Belgian Federal government (Belspo through the IAP-VI/27 and IAP-VII/05 programs), the European Union’s Seventh Framework Programme (FP7/2007-2013 under grant agreement no. 310651 SACS and no. 312483-ESTEEM2), the Flemish government in the form of long-term structural funding “Methusalem” grant METH/15/04 CASAS2, the Hercules foundation (HER/11/14), the “Strategisch Initiatief Materialen” SoPPoM program, and the Fund for Scientific Research Flanders (FWO) grants G.0349.12 and G.0B39.15. S.B. acknowledges funding from ERC Starting Grant COLOURATOMS (335078). The authors thank Prof. S. Van Aert for helpful discussions, Dr. T. De Baerdemaeker for XRD measurements, Mr. B. Dieu for the preparation of graphical material, and UOP Antwerp for the kind donation of zeolite samples.; esteem2jra4; ECASSara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot);			Approved	Most recent IF: 13.942
Call Number	c:irua:134576 c:irua:134576			Serial	4102
Permanent link to this record



Author	Ovsyannikov, S.V.; Karkin, A.E.; Morozova, N.V.; Shchennikov, V.V.; Bykova, E.; Abakumov, A.M.; Tsirlin, A.A.; Glazyrin, K.V.; Dubrovinsky, L.
Title	A hard oxide semiconductor with a direct and narrow bandgap and switchable pn electrical conduction			Type	A1 Journal article
Year	2014	Publication	Advanced materials	Abbreviated Journal	Adv Mater
Volume	26	Issue	48	Pages	8185-8191
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	An oxide semiconductor (perovskite-type Mn2O3) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos	000346480800016	Publication Date	2014-10-27
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0935-9648;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	19.791	Times cited	27	Open Access
Notes				Approved	Most recent IF: 19.791; 2014 IF: 17.493
Call Number	UA @ lucian @ c:irua:122230			Serial	1408
Permanent link to this record



Author	Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S.
Title	Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation			Type	A1 Journal article
Year	2016	Publication	Nature chemistry	Abbreviated Journal	Nat Chem
Volume	8	Issue	8	Pages	501-508
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature.
Address	Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, Germany
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language	English	Wos	000374534100019	Publication Date	2016-04-04
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1755-4330	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	25.87	Times cited	51	Open Access
Notes	S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3			Approved	Most recent IF: 25.87
Call Number	c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593			Serial	4068
Permanent link to this record



Author	O'Sullivan, M.; Hadermann, J.; Dyer, M.S.; Turner, S.; Alaria, J.; Manning, T.D.; Abakumov, A.M.; Claridge, J.B.; Rosseinsky, M.J.
Title	Interface control by chemical and dimensional matching in an oxide heterostructure			Type	A1 Journal article
Year	2016	Publication	Nature chemistry	Abbreviated Journal	Nat Chem
Volume	8	Issue	8	Pages	347-353
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Interfaces between different materials underpin both new scientific phenomena, such as the emergent behaviour at oxide interfaces, and key technologies, such as that of the transistor. Control of the interfaces between materials with the same crystal structures but different chemical compositions is possible in many materials classes, but less progress has been made for oxide materials with different crystal structures. We show that dynamical self-organization during growth can create a coherent interface between the perovskite and fluorite oxide structures, which are based on different structural motifs, if an appropriate choice of cations is made to enable this restructuring. The integration of calculation with experimental observation reveals that the interface differs from both the bulk components and identifies the chemical bonding requirements to connect distinct oxide structures.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000372505500013	Publication Date	2016-02-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1755-4330; 1755-4349	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	25.87	Times cited	28	Open Access
Notes				Approved	Most recent IF: 25.87
Call Number	UA @ lucian @ c:irua:133189			Serial	4199
Permanent link to this record



Author	McCalla, E.; Abakumov, A.M.; Saubanere, M.; Foix, D.; Berg, E.J.; Rousse, G.; Doublet, M.-L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Dominko, R.; Tarascon, J.-M.
Title	Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries			Type	A1 Journal article
Year	2015	Publication	Science	Abbreviated Journal	Science
Volume	350	Issue	350	Pages	1516-1521
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides.
Address	College de France, Chimie du Solide et de l'Energie, FRE 3677, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. ALISTORE-European Research Institute, FR CNRS 3104, 80039 Amiens, France. Reseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France. Sorbonne Universites-UPMC Univ Paris 06, 4 Place Jussieu, F-75005 Paris, France. jean-marie.tarascon@college-de-france.fr
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language	English	Wos	000366591100056	Publication Date	2015-12-17
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0036-8075	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	37.205	Times cited	281	Open Access
Notes	E.M. thanks the Fonds de Recherche du Québec–Nature et Technologies and ALISTORE–European Research Institute for funding this work, as well as the European community I3 networks for funding the neutron scattering research trip. This work was also funded by the Slovenian Research Agency research program P2-0148. This work is partially based on experiments performed at the Institut Laue Langevin. We thank J. Rodriguez-Carvajal for help with neutron scattering experiments and for fruitful discussions. We also thank M. T. Sougrati for performing the Sn-Mössbauer measurements. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02- 06CH11357. M.S. and M.-L.D. acknowledge high-performance computational resources from GENCI-CCRT/CINES (grant cmm6691). J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014-2020)/ERC Grant-Project670116-ARPEMA.			Approved	Most recent IF: 37.205; 2015 IF: 33.611
Call Number	c:irua:130202			Serial	4005
Permanent link to this record



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
Permanent link to this record



Author	Pearce, P.E.; Perez, A.J.; Rousse, G.; Saubanère, M.; Batuk, D.; Foix, D.; McCalla, E.; Abakumov, A.M.; Van Tendeloo, G.; Doublet, M.-L.; Tarascon, J.-M.
Title	Evidence for anionic redox activity in a tridimensional-ordered Li-rich positive electrode β-Li2IrO3			Type	A1 Journal article
Year	2017	Publication	Nature materials	Abbreviated Journal	Nat Mater
Volume	16	Issue	5	Pages	580-586
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	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
Permanent link to this record