Home | << 1 2 3 >> |
![]() |
Records | |||||
---|---|---|---|---|---|
Author | Batuk, D.; Batuk, M.; Morozov, V.A.; Meert, K.W.; Smet, P.F.; Poelman, D.; Abakumov, A.M.; Hadermann, J. | ||||
Title | Effect of cation vacancies on the crystal structure and luminescent properties of Ca(0.85-1.5x)Gd(x)Eu(0.1)_(0.05+0.5x)WO(4) (0<x<0.567) scheelite-based red phosphors | Type | A1 Journal article | ||
Year | 2017 | Publication | Journal of alloys and compounds | Abbreviated Journal ![]() |
J Alloy Compd |
Volume | 706 | Issue | 706 | Pages | 358-369 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The Ca0.85-1.5xGdxEu0.1_0.05-0.5xWO4 (0 < x < 0.567) series of cation-deficient scheelites is investigated to unveil the influence of the cation vacancies on the crystal structure and luminescent properties. The concentration of the vacancies is varied by the heterovalent substitution of Gd3+ for Ca2+, keeping the concentration of the Eu3+ luminescent centers constant in all compounds of the series. The crystal structure of the materials is studied using a combination of transmission electron microscopy and synchrotron X-ray powder diffraction. At low vacancy concentration (x = 0.1, 0.2), cations and cation vacancies are randomly distributed in the structure, and the materials preserve the I41/a symmetry of the parent scheelite structure [x = 0.1: a = 5.25151(1) Å, c = 11.39479(2) Å; x = 0.2: a = 5.25042(1) Å, c = 11.41335(2) Å]. At higher concentration, the cation-vacancy ordering gives rise to incommensurately modulated structures. The x = 0.3 structure has a (3 + 2)D tetragonal symmetry [superspace group I41/a(a,b,0)00(-b,a,0)00, a = 5.24700(1) Å, c = 11.45514(3) Å, q1 = 0.51637(14)a* + 0.80761(13)b*, q2 = -0.80761a* + 0.51637b*]. At x = 0.4, the scheelite basic cell undergoes a monoclinic distortion with the formation of the (3 + 1)D structure [superspace group I2/b(a,b,0)00, a = 5.23757(1) Å, b = 5.25035(1) Å, c = 11.45750(2) Å, g = 90.5120(2) o, q = 0.54206(8)a* + 0.79330(8)b*]. In both structures, the antiphase Ca and (Gd,Eu) occupancy modulations indicate that the ordering between the A cations and vacancies also induces partial Ca/(Gd,Eu) cation ordering. Further increase of the Gd3þ content up to x = 0.567 leads to the formation of a monoclinic phase (space group C2/c) with the Eu2/3WO4-type structure. Despite the difference in the cation-vacancy ordering patterns, all materials in the series demonstrate very similar quantum efficiency and luminescence decay lifetimes. However, the difference in the local coordination environment of the A cation species noticeably affects the line width and the multiplet splitting of the 4f6-4f6 transitions. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000397997300045 | Publication Date | 2017-02-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0925-8388 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.133 | Times cited | 2 | Open Access | OpenAccess |
Notes | This research was supported by FWO (Flanders Research Foundation, project G039211N). V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741).We are grateful to the ESRF for granting the beamtime at the ID22 beamline and to Andy Fitch for the support during the experiment. | Approved | Most recent IF: 3.133 | ||
Call Number | EMAT @ emat @ c:irua:142367 | Serial | 4581 | ||
Permanent link to this record | |||||
Author | Ciocarlan, R.-G.; Seftel, E.M.; Gavrila, R.; Suchea, M.; Batuk, M.; Mertens, M.; Hadermann, J.; Cool, P. | ||||
Title | Spinel nanoparticles on stick-like Freudenbergite nanocomposites as effective smart-removal photocatalysts for the degradation of organic pollutants under visible light | Type | A1 Journal article | ||
Year | 2020 | Publication | Journal Of Alloys And Compounds | Abbreviated Journal ![]() |
J Alloy Compd |
Volume | 820 | Issue | Pages | 153403 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) | ||||
Abstract | A series of mixed nanocomposite materials was synthetized, containing a Ferrite phase type Zn1-xNixFe2O4 and a Freudenbergite phase type Na2Fe2Ti6O16, where x = 0; 0.2; 0.4; 0.6; 0.8; 1. The choice for this combination is based on the good adsorption properties of Freudenbergite for dye molecules, and the small bandgap energy of Ferrite spinel, allowing activation of the catalysts under visible light irradiation. A two steps synthesis protocol was used to obtain the smart-removal nanocomposites. Firstly, the spinel structure was obtained via the co-precipitation route followed by the addition of the Ti-source and formation of the Freudenbergite system. The role of cations on the formation mechanism and an interesting interchange of cations between spinel and Freudenbergite structures was clarified by a TEM study. Part of the Ti4+ penetrated the spinel structure and, at the same time, part of the Fe3+ formed the Freudenbergite system. The photocatalytic activity was studied under visible light, reaching for the best catalysts a 67% and 40% mineralization degree for methylene blue and rhodamine 6G respectively, after 6 h of irradiation. In the same conditions, the well-known commercial P25 (Degussa) managed to mineralize only 12% and 3% of methylene blue and rhodamine 6G, respectively. Due to the remarkable magnetic properties of Ferrites, a convenient recovery and reuse of the catalysts is possible after the photocatalytic tests. Based on the excellent catalytic performance of the nanocomposites under visible light and their ease of separation out of the solution after the catalytic reaction, the newly developed composite catalysts are considered very effective for wastewater treatment. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000507854700130 | Publication Date | 2019-12-15 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0925-8388 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.2 | Times cited | Open Access | OpenAccess | |
Notes | The authors acknowledge the FWO-Flanders (project nr. G038215N) for financial support. | Approved | Most recent IF: 6.2; 2020 IF: 3.133 | ||
Call Number | EMAT @ emat @c:irua:166447 | Serial | 6342 | ||
Permanent link to this record | |||||
Author | Batuk, M.; Turner, S.; Abakumov, A.M.; Batuk, D.; Hadermann, J.; Van Tendeloo, G. | ||||
Title | Atomic structure of defects in anion-deficient perovskite-based ferrites with a crystallographic shear structure | Type | A1 Journal article | ||
Year | 2014 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 53 | Issue | 4 | Pages | 2171-2180 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Crystallographic shear (CS) planes provide a new structure-generation mechanism in the anion-deficient perovskites containing lone-pair cations. Pb2Sr2Bi2Fe6O16, a new n = 6 representative of the AnBnO3n2 homologous series of the perovskite-based ferrites with the CS structure, has been synthesized using the solid-state technique. The structure is built of perovskite blocks with a thickness of four FeO6 octahedra spaced by double columns of FeO5 edge-sharing distorted tetragonal pyramids, forming 1/2[110](101)p CS planes (space group Pnma, a = 5.6690(2) Å, b = 3.9108(1) Å, c = 32.643(1) Å). Pb2Sr2Bi2Fe6O16 features a wealth of microstructural phenomena caused by the flexibility of the CS planes due to the variable ratio and length of the constituting fragments with {101}p and {001}p orientation. This leads to the formation of waves, hairpins, Γ-shaped defects, and inclusions of the hitherto unknown layered anion-deficient perovskites Bi2(Sr,Pb)Fe3O8.5 and Bi3(Sr,Pb)Fe4O11.5. Using a combination of diffraction, imaging, and spectroscopic transmission electron microscopy techniques this complex microstructure was fully characterized, including direct determination of positions, chemical composition, and coordination number of individual atomic species. The complex defect structure makes these perovskites particularly similar to the CS structures in ReO3-type oxides. The flexibility of the CS planes appears to be a specific feature of the Sr-based system, related to the geometric match between the SrO perovskite layers and the {100}p segments of the CS planes. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000332144100039 | Publication Date | 2014-01-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 6 | Open Access | |
Notes | Countatoms; FWO | Approved | Most recent IF: 4.857; 2014 IF: 4.762 | ||
Call Number | UA @ lucian @ c:irua:113507 | Serial | 198 | ||
Permanent link to this record | |||||
Author | Batuk, D.; Batuk, M.; Abakumov, A.M.; Tsirlin, A.A.; McCammon, C.M.; Dubrovinsky, L.; Hadermann, J. | ||||
Title | Effect of lone-electron-pair cations on the orientation of crystallographic shear planes in anion-deficient perovskites | Type | A1 Journal article | ||
Year | 2013 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 52 | Issue | 17 | Pages | 10009-10020 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Factors affecting the structure and orientation of the crystallographic shear (CS) planes in anion-deficient perovskites are investigated using the (Pb1−zSrz)1−xFe1+xO3−y perovskites as a model system. The orientation of the CS planes in the system varies unevenly with z. A comparison of the structures with different CS planes revels that the orientation of the CS planes is governed mainly by the stereochemical activity of the lone-electron-pair cations inside the perovskite blocks. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000326129000037 | Publication Date | 2013-08-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 11 | Open Access | |
Notes | Fwo | Approved | Most recent IF: 4.857; 2013 IF: 4.794 | ||
Call Number | UA @ lucian @ c:irua:111394 | Serial | 822 | ||
Permanent link to this record | |||||
Author | Batuk, M.; Batuk, D.; Tsirlin, A.A.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G. | ||||
Title | Homologous series of layered perovskites An+1BnO3n-1Cl : crystal and magnetic structure of a new oxychloride Pb4BiFe4O11Cl | Type | A1 Journal article | ||
Year | 2013 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 52 | Issue | 4 | Pages | 2208-2218 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The nuclear and magnetic structure of a novel oxychloride Pb4BiFe4O11Cl has been studied over the temperature range 1.5700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb4BiFe4O11Cl is built of truncated (Pb,Bi)3Fe4O11 quadruple perovskite blocks separated by CsCl-type (Pb,Bi)2Cl slabs. The perovskite blocks consist of two layers of FeO6 octahedra located between two layers of FeO5 tetragonal pyramids. The FeO6 octahedra rotate about the c axis, resulting in a √2ap × √2ap × c superstructure. Below TN = 595(17) K, Pb4BiFe4O11Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μB on the octahedral and square-pyramidal iron sites, respectively. Pb4BiFe4O11Cl can be considered a member of the perovskite-based An+1BnO3n1Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000315255200067 | Publication Date | 2013-02-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 6 | Open Access | |
Notes | Countatoms | Approved | Most recent IF: 4.857; 2013 IF: 4.794 | ||
Call Number | UA @ lucian @ c:irua:106185 | Serial | 1486 | ||
Permanent link to this record | |||||
Author | Abakumov, A.M.; Hadermann, J.; Batuk, M.; d' Hondt, H.; Tyablikov, O.A.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. | ||||
Title | Slicing the Perovskite structure with crystallographic shear planes : the AnBnO3n-2 homologous series | Type | A1 Journal article | ||
Year | 2010 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 49 | Issue | 20 | Pages | 9508-9516 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A new AnBnO3n−2 homologous series of anion-deficient perovskites has been evidenced by preparation of the members with n = 5 (Pb2.9Ba2.1Fe4TiO13) and n = 6 (Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16) in a single phase form. The crystal structures of these compounds were determined using a combination of transmission electron microscopy and X-ray and neutron powder diffraction (S.G. Ammm, a = 5.74313(7), b = 3.98402(4), c = 26.8378(4) Å, RI = 0.035, RP = 0.042 for Pb2.9Ba2.1Fe4TiO13 and S.G. Imma, a = 5.7199(1), b = 3.97066(7), c = 32.5245(8) Å, RI = 0.032, RP = 0.037 for Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16). The crystal structures of the AnBnO3n−2 homologues are formed by slicing the perovskite structure with (01)p crystallographic shear (CS) planes. The shear planes remove a layer of oxygen atoms and displace the perovskite blocks with respect to each other by the 1/2[110]p vector. The CS planes introduce edge-sharing connections of the transition metal−oxygen polyhedra at the interface between the perovskite blocks. This results in intrinsically frustrated magnetic couplings between the perovskite blocks due to a competition of the exchange interactions between the edge- and the corner-sharing metal−oxygen polyhedra. Despite the magnetic frustration, neutron powder diffraction and Mssbauer spectroscopy reveal that Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 are antiferromagnetically ordered below TN = 407 and 343 K, respectively. The Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 compounds are in a paraelectric state in the 5−300 K temperature range. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000282783400051 | Publication Date | 2010-09-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 23 | Open Access | |
Notes | Esteem 026019; Fwo | Approved | Most recent IF: 4.857; 2010 IF: 4.326 | ||
Call Number | UA @ lucian @ c:irua:84963 | Serial | 3041 | ||
Permanent link to this record | |||||
Author | Abakumov, A.M.; Batuk, M.; Tsirlin, A.A.; Tyablikov, O.A.; Sheptyakov, D.V.; Filimonov, D.S.; Pokholok, K.V.; Zhidal, V.S.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; | ||||
Title | Structural and magnetic phase transitions in the AnBnO3n-2 anion-deficient perovskites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 | Type | A1 Journal article | ||
Year | 2013 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 52 | Issue | 14 | Pages | 7834-7843 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Novel anion-deficient perovskite-based ferrites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 were synthesized by solid-state reaction in air. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 belong to the perovskite-based AnBnO3n2 homologous series with n = 5 and 6, respectively, with a unit cell related to the perovskite subcell ap as ap√2 × ap × nap√2. Their structures are derived from the perovskite one by slicing it with 1/2[110]p(1̅01)p crystallographic shear (CS) planes. The CS operation results in (1̅01)p-shaped perovskite blocks with a thickness of (n 2) FeO6 octahedra connected to each other through double chains of edge-sharing FeO5 distorted tetragonal pyramids which can adopt two distinct mirror-related configurations. Ordering of chains with a different configuration provides an extra level of structure complexity. Above T ≈ 750 K for Pb2Ba2BiFe5O13 and T ≈ 400 K for Pb1.5Ba2.5Bi2Fe6O16 the chains have a disordered arrangement. On cooling, a second-order structural phase transition to the ordered state occurs in both compounds. Symmetry changes upon phase transition are analyzed using a combination of superspace crystallography and group theory approach. Correlations between the chain ordering pattern and octahedral tilting in the perovskite blocks are discussed. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 undergo a transition into an antiferromagnetically (AFM) ordered state, which is characterized by a G-type AFM ordering of the Fe magnetic moments within the perovskite blocks. The AFM perovskite blocks are stacked along the CS planes producing alternating FM and AFM-aligned FeFe pairs. In spite of the apparent frustration of the magnetic coupling between the perovskite blocks, all n = 4, 5, 6 AnFenO3n2 (A = Pb, Bi, Ba) feature robust antiferromagnetism with similar Néel temperatures of 623632 K. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000322087100006 | Publication Date | 2013-02-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669;1520-510X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 10 | Open Access | |
Notes | Countatoms | Approved | Most recent IF: 4.857; 2013 IF: 4.794 | ||
Call Number | UA @ lucian @ c:irua:109213 | Serial | 3196 | ||
Permanent link to this record | |||||
Author | Cassidy, S.J.; Batuk, M.; Batuk, D.; Hadermann, J.; Woodruff, D.N.; Thompson, A.L.; Clarke, S.J. | ||||
Title | Complex Microstructure and Magnetism in Polymorphic CaFeSeO | Type | A1 Journal article | ||
Year | 2016 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 55 | Issue | 55 | Pages | 10714-10726 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The structural complexity of the antiferromagnetic oxide selenide CaFeSeO is described. The compound contains puckered FeSeO layers composed of FeSe2O2 tetrahedra sharing all their vertexes. Two polymorphs coexist that can be derived from an archetype BaZnSO structure by cooperative tilting of the FeSe2O2 tetrahedra. The polymorphs differ in the relative arrangement of the puckered layers of vertex-linked FeSe2O2 tetrahedra. In a noncentrosymmetric Cmc21 polymorph (a = 3.89684(2) A, b = 13.22054(8) A, c = 5.93625(2) A) the layers are related by the C-centering translation, while in a centrosymmetric Pmcn polymorph, with a similar cell metric (a = 3.89557(6) A, b = 13.2237(6) A, c = 5.9363(3) A), the layers are related by inversion. The compound shows long-range antiferromagnetic order below a Neel temperature of 159(1) K with both polymorphs showing antiferromagnetic coupling via Fe-O-Fe linkages and ferromagnetic coupling via Fe-Se-Fe linkages within the FeSeO layers. The magnetic susceptibility also shows evidence for weak ferromagnetism which is modeled in the refinements of the magnetic structure as arising from an uncompensated spin canting in the noncentrosymmetric polymorph. There is also a spin glass component to the magnetism which likely arises from the disordered regions of the structure evident in the transmission electron microscopy. | ||||
Address | Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000385785700085 | Publication Date | 2016-10-05 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 6 | Open Access | |
Notes | We acknowledge the financial support of the EPSRC (Grants EP/I017844/1 and EP/M020517/1), the Leverhulme Trust (RPG-2014-221), and the Diamond Light Source (studentship support for S. J. Cassidy). We thank the ESTEEM2 network for enabling the electron microscopy investigations and the ISIS facility and the Diamond Light Source Ltd. for the award of beam time. We thank Dr. P. Manuel for assistance on WISH, Dr. R. I. Smith for assistance on GEM and POLARIS, and Dr. C. Murray and Dr. A. Baker for assistance on I11. | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @ c:irua:136823 | Serial | 4312 | ||
Permanent link to this record | |||||
Author | Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J. | ||||
Title | Synthesis of MAX Phases in the Zr-Ti-Al-C System | Type | A1 Journal article | ||
Year | 2017 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 56 | Issue | 56 | Pages | 3489-3498 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000397171100045 | Publication Date | 2017-03-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 26 | Open Access | OpenAccess |
Notes | Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @ c:irua:141794 | Serial | 4491 | ||
Permanent link to this record | |||||
Author | Batuk, D.; Batuk, M.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Tyablikov, O.A.; Hadermann, J.; Abakumov, A.M. | ||||
Title | Crystal Structure, Defects, Magnetic and Dielectric Properties of the Layered Bi3n+1Ti7Fe3n-3,O9n+11 Perovskite-Anatase lntergrowths | Type | A1 Journal article | ||
Year | 2017 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 56 | Issue | 56 | Pages | 931-942 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The Bi3n+1Ti7Fe3n-3,O9n+11 materials are built of (001)(p) plane parallel perovskite blocks with a thickness of n (Ti,Fe)O-6 octahedra, separated by periodic translational interfaces. The interfaces are based on anatase-like chains of edge -sharing (Ti,Fe)O-6 octahedra. Together with the octahedra of the perovskite blocks, they create S-shaped tunnels stabilized by lone pair Bi3+ cations. In this work, the structure of the n = 4-6 Bi3n+1Ti7Fe3n-3,O9n+11 homologues is analyzed in detail using advanced transmission electron microscopy, powder X-ray diffraction, and Mossbauer spectroscopy. The connectivity of the anatase-like chains to the perovskite blocks results in,a 3ap periodicity along the interfaces, so that they can be located either on top of each other or with shifts of +/- a(p) along [100](p). The ordered arrangement of the interfaces gives rise to orthorhombic Immm and monoclinic A2/m polymorphs with the unit cell parameters a = 3a(p), b = b(p), c = 2(n + 1)c(p) and a = 3a(p), b = b(p), c = 2(n + 1)c(p) – a(p), respectively. While the n = 3 compound is orthorhombic, the monoclinic modification is more favorable in higher homologues. The Bi3n+1Ti7Fe3n-3,O9n+11 structures demonstrate intricate patterns of atomic displacements in the perovskite blocks, which are supported by the stereochemical activity of the Bi3+ cations. These patterns are coupled to the cationic coordination of the oxygen atoms in the (Ti,Fe)O-2 layers at the border of the perovskite blocks. The coupling is strong in the 1/ = 3, 4 homologues, but gradually reduces with the increasing thickness of the perovskite blocks, so that, in the n = 6 compound, the dominant mode of atomic displacements is aligned along the interface planes. The displacements in the adjacent perovskite blocks tend to order antiparallel, resulting in an overall antipolar structure. The Bi3n+1Ti7Fe3n-3,O9n+11 materials demonstrate an unusual diversity of structure defects. The n = 4-6 homologues are robust antiferromagnets below T-N = 135, 220, and 295 K, respectively. They show a high dielectric constant that weakly increases with temperature and is relatively insensitive to the Ti/Fe ratio. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Easton, Pa | Editor | ||
Language | Wos | 000392262400029 | Publication Date | 2016-12-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 3 | Open Access | Not_Open_Access |
Notes | ; The work was supported by the Russian Science Foundation (grant 14-13-00680). ; | Approved | Most recent IF: 4.857 | ||
Call Number | UA @ lucian @ c:irua:141471 | Serial | 4495 | ||
Permanent link to this record | |||||
Author | Jin, L.; Batuk, M.; Kirschner, F.K.K.; Lang, F.; Blundell, S.J.; Hadermann, J.; Hayward, M.A. | ||||
Title | Exsolution of SrO during the Topochemical Conversion of LaSr3CoRuO8to the Oxyhydride LaSr3CoRuO4H4 | Type | A1 Journal article | ||
Year | 2019 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 58 | Issue | 21 | Pages | 14863-14870 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Reaction of the n = 1 Ruddlesden-Popper oxide LaSr3CoRuO8 with CaH2 yields the oxyhydride phase LaSr3CoRuO4H4 via topochemical anion-exchange. Close inspection of X-ray and neutron powder diffraction data in combination with HAADF-STEM images reveals that nanoparticles of SrO are exsolved from the system during the reaction, with the change in cation stoichiometry accommodated by the inclusion of n > 1 (Co/Ru)nOn+1H2n ‘perovskite’ layers into the Ruddlesden-Popper stacking sequence. This novel pseudo-topochemical process offers a new route for the formation of n > 1 Ruddlesden-Popper structured materials. Magnetization data are consistent with a LaSr3Co1+Ru2+O4H4 (Co1+, d8, S = 1; Ru2+, d6, S = 0) oxidation/spin state combination. Neutron diffraction and μ+SR data show no evidence for long-range magnetic order down to 2 K, suggesting the diamagnetic Ru2+ centers impede the Co-Co magnetic exchange interactions. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000494894400062 | Publication Date | 2019-11-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | 1 | Open Access | |
Notes | We thank P. Manuel for assistance collecting the neutron powder diffraction data. We thank The Leverhulme Trust grant award RPG-2014-366 “Topochemical reduction of 4d and 5d transition metal oxides” for supporting this work. Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Investigation by TEM was supported through the FWO grant G035619N. | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @c:irua:164625 | Serial | 5434 | ||
Permanent link to this record | |||||
Author | Xu, X.; Jones, M.A.; Cassidy, S.J.; Manuel, P.; Orlandi, F.; Batuk, M.; Hadermann, J.; Clarke, S.J. | ||||
Title | Magnetic Ordering in the Layered Cr(II) Oxide Arsenides Sr2CrO2Cr2As2and Ba2CrO2Cr2As2 | Type | A1 Journal article | ||
Year | 2020 | Publication | Inorganic Chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 59 | Issue | 21 | Pages | 15898-15912 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Sr2CrO2Cr2As2 and Ba2CrO2Cr2As2 with Cr2+ ions in CrO2 sheets and in CrAs layers crystallize with the Sr2Mn3Sb2O2 structure (space group I4/mmm, Z = 2) and lattice parameters a = 4.00800(2) Å, c = 18.8214(1) Å (Sr2CrO2Cr2As2) and a = 4.05506(2) Å, c = 20.5637(1) Å (Ba2CrO2Cr2As2) at room temperature. Powder neutron diffraction reveals checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the arsenide layers below TN1Sr, of 600(10) K (Sr2CrO2Cr2As2) and TN1Ba 465(5) K (Ba2CrO2Cr2As2) with the moments initially directed perpendicular to the layers in both compounds. Checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the oxide layer below 230(5) K for Ba2CrO2Cr2As2 occurs with these moments also perpendicular to the layers, consistent with the orientation preferences of d4 moments in the two layers. In contrast, below 330(5) K in Sr2CrO2Cr2As2, the oxide layer Cr2+ moments are initially oriented in the CrO2 plane; but on further cooling, these moments rotate to become perpendicular to the CrO2 planes, while the moments in the arsenide layers rotate by 90° with the moments on the two sublattices remaining orthogonal throughout [behavior recently reported independently by Liu et al. [Liu et al. Phys. Rev. B 2018, 98, 134416]]. In Sr2CrO2Cr2As2, electron diffraction and high resolution powder X-ray diffraction data show no evidence for a structural distortion that would allow the two Cr2+ sublattices to couple, but high resolution neutron powder diffraction data suggest a small incommensurability between the magnetic structure and the crystal structure, which may account for the coupling of the two sublattices and the observed spin reorientation. The saturation values of the Cr2+ moments in the CrO2 layers (3.34(1) μB (for Sr2CrO2Cr2As2) and 3.30(1) μB (for Ba2CrO2Cr2As2)) are larger than those in the CrAs layers (2.68(1) μB for Sr2CrO2Cr2As2 and 2.298(8) μB for Ba2CrO2Cr2As2) reflecting greater covalency in the arsenide layers. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000588738100035 | Publication Date | 2020-11-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.6 | Times cited | Open Access | OpenAccess | |
Notes | We thank the UK EPSRC (EP/M020517/1 and EP/P018874/ 1) and the Leverhulme Trust (RPG-2014-221) for funding and the ISIS pulsed neutron and muon source (RB1610357 and RB1700075) and the Diamond Light Source Ltd. (EE13284 and EE18786) for the award of beam time. We thank Dr. A. Baker and Dr. C. Murray for support on I11. | Approved | Most recent IF: 4.6; 2020 IF: 4.857 | ||
Call Number | EMAT @ emat @c:irua:176058 | Serial | 6704 | ||
Permanent link to this record | |||||
Author | Savina, A.A.; Saiutina, V.V.; Morozov, A.V.; Boev, A.O.; Aksyonov, D.A.; Dejoie, C.; Batuk, M.; Bals, S.; Hadermann, J.; Abakumov, A.M. | ||||
Title | Chemistry, local molybdenum clustering, and electrochemistry in the Li2+xMo1-xO3 solid solutions | Type | A1 Journal article | ||
Year | 2022 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 61 | Issue | 14 | Pages | 5637-5652 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A broad range of cationic nonstoichiometry has been demonstratedfor the Li-rich layered rock-salt-type oxide Li2MoO3, which has generally been considered as a phase with a well-defined chemical composition. Li2+xMo1-xO3(-0.037 <= x <= 0.124) solid solutions were synthesized via hydrogen reduction ofLi2MoO4in the temperature range of 650-1100 degrees C, withxdecreasing with theincrease of the reduction temperature. The solid solutions adopt a monoclinicallydistorted O3-type layered average structure and demonstrate a robust localordering of the Li cations and Mo3triangular clusters within the mixed Li/Mocationic layers. The local structure was scrutinized in detail by electron diffractionand aberration-corrected scanning transmission electron microcopy (STEM),resulting in an ordering model comprising a uniform distribution of the Mo3clusters compatible with local electroneutrality and chemical composition. The geometry of the triangular clusters with their oxygenenvironment (Mo3O13groups) has been directly visualized using differential phase contrast STEM imaging. The established localstructure was used as input for density functional theory (DFT)-based calculations; they support the proposed atomic arrangementand provide a plausible explanation for the staircase galvanostatic charge profiles upon electrochemical Li+extraction fromLi2+xMo1-xO3in Li cells. According to DFT, all electrochemical capacity in Li2+xMo1-xO3solely originates from the cationic Moredox process, which proceeds via oxidation of the Mo3triangular clusters into bent Mo3chains where the electronic capacity of the clusters depends on the initial chemical composition and Mo oxidation state defining the width of the first charge low-voltageplateau. Further oxidation at the high-voltage plateau proceeds through decomposition of the Mo3chains into Mo2dimers and further into individual Mo6+cations | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000789034200023 | Publication Date | 2022-04-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.6 | Times cited | 3 | Open Access | Not_Open_Access |
Notes | The authors acknowledge Russian Science Foundation (grant 20-43-01012) and Research Foundation Flanders (FWO Vlaanderen, project number G0F1320N) for financial support. The authors are grateful to AICF of Skoltech for providing access to electron microscopy equipment. The authors are grateful to Prof. G. Van Tendeloo for discussing the results. | Approved | Most recent IF: 4.6 | ||
Call Number | UA @ admin @ c:irua:188631 | Serial | 7079 | ||
Permanent link to this record | |||||
Author | Sheath, B.C.; Xu, X.; Manuel, P.; Hadermann, J.; Batuk, M.; O'Sullivan, J.; Bonilla, R.S.; Clarke, S.J. | ||||
Title | Structures and magnetic ordering in layered Cr oxide arsenides Sr₂CrO₂Cr₂OAs₂ and Sr₂CrO₃CrAs | Type | A1 Journal article | ||
Year | 2022 | Publication | Inorganic chemistry | Abbreviated Journal ![]() |
Inorg Chem |
Volume | 61 | Issue | 31 | Pages | 10-12385 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Two novel chromium oxide arsenide materials have been synthesized, Sr2CrO2Cr2OAs2 (i.e., Sr2Cr3As2O3) and Sr2CrO3CrAs (i.e., Sr2Cr2AsO3), both of which contain chromium ions in two distinct layers. Sr2CrO2Cr2OAs2 was targeted following electron microscopy measurements on a related phase. It crystallizes in the space group P4/mmm and accommodates distorted CrO4As2 octahedra containing Cr2+ and distorted CrO(2)As(4 )octahedra containing Cr3+. In contrast, Sr2CrO3CrAs incorporates Cr3+ in CrO5 square-pyramidal coordination in [Sr2CrO3](+) layers and Cr2+ ions in CrAs(4 )tetrahedra in [CrAs](-) layers and crystallizes in the space group P4/nmm. Powder neutron diffraction data reveal antiferromagnetic ordering in both compounds. In Sr2CrO3CrAs the Cr2+ moments in the [CrAs](-) layers exhibit long-range ordering, while the Cr3+ moments in the [Sr2CrO3](+) layers only exhibit short-range ordering. However, in Sr2CrO2Cr2OAs2, both the Cr(2+ )moments in the CrO4As2 environments and the Cr3+ moments in the CrO2As4 polyhedra are long-range-ordered below 530(10) K. Above this temperature, only the Cr3+ moments are ordered with a Neel temperature slightly in excess of 600 K. A subtle structural change is evident in Sr2CrO2Cr2OAs2 below the magnetic ordering transitions. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000841943600001 | Publication Date | 2022-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.6 | Times cited | Open Access | OpenAccess | |
Notes | Approved | Most recent IF: 4.6 | |||
Call Number | UA @ admin @ c:irua:190007 | Serial | 7215 | ||
Permanent link to this record | |||||
Author | Ranjbar, S.; Hadipour, A.; Vermang, B.; Batuk, M.; Hadermann, J.; Garud, S.; Sahayaraj, S.; Meuris, M.; Brammertz, G.; da Cunha, A.F.; Poortmans, J. | ||||
Title | P-N Junction Passivation in Kesterite Solar Cells by Use of Solution-Processed TiO2 Layer | Type | A1 Journal article | ||
Year | 2017 | Publication | IEEE journal of photovoltaics | Abbreviated Journal ![]() |
Ieee J Photovolt |
Volume | 7 | Issue | 7 | Pages | 1130-1135 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this work, we used a solution-processed TiO2 layer between Cu2ZnSnSe4 and CdS buffer layer to reduce the recombination at the p–n junction. Introducing the TiO2 layer showed a positive impact on VOC but fill factor and efficiency decreased. Using a KCN treatment, we could create openings in the TiO2 layer, as confirmed by transmission electron microscopy measurements. Formation of these openings in the TiO2 layer led to the improvement of the short-circuit current, fill factor, and the efficiency of the modified solar cells. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000404258900026 | Publication Date | 2017-04-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2156-3381 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.712 | Times cited | 2 | Open Access | OpenAccess |
Notes | This work was supported in part by the European Union’s Horizon 2020 research and innovation program under Grant 640868, in part by the Flemish government, Department Economy, Science and Innovation, in part by the FEDER funds through the COMPETE 2020 Programme, and in part by the National Funds through FCT – Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013. The work of S. Ranjbar was supported by the Portuguese Science and Technology Foundation through Ph.D. grant SFRH/BD/78409/2011. The work of B. Vermang was supported by the Flemish Research Foundation FWO (mandate 12O4215N). | Approved | Most recent IF: 3.712 | ||
Call Number | EMAT @ emat @ c:irua:143986 | Serial | 4583 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. | ||||
Title | Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations | Type | A1 Journal article | ||
Year | 2016 | Publication | Dental Materials | Abbreviated Journal ![]() |
Dent Mater |
Volume | 32 | Issue | 32 | Pages | e327-e337 |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | OBJECTIVE: The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. METHODS: Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n=6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n=10), single edge V-notched beam (SEVNB) fracture toughness (n=8) and Vickers hardness (n=10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n=3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha=0.05). RESULTS: Lowering the alumina content below 0.25wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. SIGNIFICANCE: Three different approaches were compared to improve the translucency of 3Y-TZP ceramics. | ||||
Address | KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, Belgium | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000389516400003 | Publication Date | 2016-10-06 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0109-5641 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.07 | Times cited | Open Access | ||
Notes | The authors acknowledge the Research Fund of KU Leu- ven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post- doctoral fellowship (PDM/15/153). We thank M. Peumans for the translucency measurements. | Approved | Most recent IF: 4.07 | ||
Call Number | EMAT @ emat @ c:irua:136821 | Serial | 4313 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Inokoshi, M.; Batuk, M.; Hadermann, J.; Naert, I.; Van Meerbeek, B.; Vleugels, J. | ||||
Title | Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations | Type | A1 Journal article | ||
Year | 2016 | Publication | Dental materials | Abbreviated Journal ![]() |
Dent Mater |
Volume | 32 | Issue | 12 | Pages | E327-E337 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Objective. The aim was to evaluate the optical properties, mechanical properties and aging stability of yttria-stabilized zirconia with different compositions, highlighting the influence of the alumina addition, Y2O3 content and La2O3 doping on the translucency. Methods. Five different Y-TZP zirconia powders (3 commercially available and 2 experimentally modified) were sintered under the same conditions and characterized by X-ray diffraction with Rietveld analysis and scanning electron microscopy (SEM). Translucency (n = 6/group) was measured with a color meter, allowing to calculate the translucency parameter (TP) and the contrast ratio (CR). Mechanical properties were appraised with four-point bending strength (n = 10), single edge V-notched beam (SEVNB) fracture toughness (n = 8) and Vickers hardness (n = 10). The aging stability was evaluated by measuring the tetragonal to monoclinic transformation (n = 3) after accelerated hydrothermal aging in steam at 134 degrees C, and the transformation curves were fitted by the Mehl-Avrami-Johnson (MAJ) equation. Data were analyzed by one-way ANOVA, followed by Tukey's HSD test (alpha = 0.05). Results. Lowering the alumina content below 0.25 wt.% avoided the formation of alumina particles and therefore increased the translucency of 3Y-TZP ceramics, but the hydrothermal aging stability was reduced. A higher yttria content (5 mol%) introduced about 50% cubic zirconia phase and gave rise to the most translucent and aging-resistant Y-TZP ceramics, but the fracture toughness and strength were considerably sacrificed. 0.2 mol% La2O3 doping of 3Y-TZP tailored the grain boundary chemistry and significantly improved the aging resistance and translucency. Although the translucency improvement by La2O3 doping was less effective than for introducing a substantial amount of cubic zirconia, this strategy was able to maintain the mechanical properties of typical 3Y-TZP ceramics. Significance. Three different approaches were compared to improve the translucency of 3YTZP ceramics. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Copenhagen | Editor | ||
Language | Wos | 000389516400003 | Publication Date | ||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0109-5641 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 4.07 | Times cited | 47 | Open Access | |
Notes | Approved | Most recent IF: 4.07 | |||
Call Number | UA @ lucian @ c:irua:140246 | Serial | 4447 | ||
Permanent link to this record | |||||
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 Pb2.4Ba2.6Fe2Sc2TiO13 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. | ||||
Address | |||||
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 | ||
Permanent link to this record | |||||
Author | Charkin, D.O.; Akinfiev, V.S.; Alekseeva, A.M.; Batuk, M.; Abakumov, A.M.; Kazakov, S.M. | ||||
Title | Synthesis and cation distribution in the new bismuth oxyhalides with the Sillen-Aurivillius intergrowth structures | Type | A1 Journal article | ||
Year | 2015 | Publication | Journal of the Chemical Society : Dalton transactions | Abbreviated Journal ![]() |
Dalton T |
Volume | 44 | Issue | 44 | Pages | 20568-20576 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | About 20 new compounds with the Sillen-Aurivillius intergrowth structure, (MeMeBi3Nb2O11X)-Me-1-Bi-2 (Me-1 = Pb, Sr, Ba; Me-2 = Ca, Sr, Ba; X = Cl, Br, I), have been prepared. They are composed of stacking of [ANb(2)O(7)] perovskite blocks, fluorite-type [M2O2] blocks and halogen sheets. The cation distribution between the fluorite and perovskite layers has been studied for Ba2Bi3Nb2O11I, Ca1.25Sr0.75Bi3Nb2O11Cl, BaCaBi3Nb2O11Br and Sr2Bi3Nb2O11Cl. The smaller Me cations tend to reside in the perovskite block while the larger ones are situated in the fluorite-type block. The distribution of the elements was confirmed for BaCaBi3Nb2O11Br using energy dispersive X-ray analysis combined with scanning transmission electron microscopy (STEM-EDX). An electron diffraction study of this compound reveals a local symmetry lowering caused by weakly correlated rotation of NbO6 octahedra. Based on our findings, we suggest a new stability criterion for mixed-layer structures, which is that net charges of any two consecutive layers do not compensate for each other and only the whole layer sequence is electroneutral. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000365411500036 | Publication Date | 2015-10-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0300-9246; 1477-9226; 1472-7773 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.029 | Times cited | 5 | Open Access | |
Notes | Approved | Most recent IF: NA | |||
Call Number | UA @ lucian @ c:irua:130330 | Serial | 4256 | ||
Permanent link to this record | |||||
Author | Mallick, S.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Hayward, M.A. | ||||
Title | The crystal and defect structures of polar KBiNb2O7 | Type | A1 Journal article | ||
Year | 2022 | Publication | Journal of the Chemical Society : Dalton transactions | Abbreviated Journal ![]() |
Dalton T |
Volume | 51 | Issue | 5 | Pages | 1866-1873 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0. ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately an ~11% chance of being defective – a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000741540300001 | Publication Date | 2022-01-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1477-9226 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 4 | Times cited | Open Access | OpenAccess | |
Notes | Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford/Warwick Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE18786). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC (RB 2000148). SM thanks Somerville College for an Oxford Ryniker Lloyd scholarship. PSH and WZ thank the National Science Foundation (DMR-2002319) for support. | Approved | Most recent IF: 4 | ||
Call Number | EMAT @ emat @c:irua:185504 | Serial | 6951 | ||
Permanent link to this record | |||||
Author | Kamminga, M.E.; Batuk, M.; Hadermann, J.; Clarke, S.J. | ||||
Title | Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide | Type | A1 Journal article | ||
Year | 2020 | Publication | Communications Materials | Abbreviated Journal ![]() |
Commun Mater |
Volume | 1 | Issue | 1 | Pages | 82 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Topological superconductivity is of great contemporary interest and has been proposed in doped Bi<sub>2</sub>Se<sub>3</sub>, in which electron-donating atoms such as Cu, Sr or Nb have been intercalated into the Bi<sub>2</sub>Se<sub>3</sub>structure. For Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>, with<italic>T</italic><sub>c</sub> ~ 3 K, it is assumed in the literature that Nb is inserted in the van der Waals gap. However, in this work an alternative origin for the superconductivity in Nb-doped Bi<sub>2</sub>Se<sub>3</sub>is established. In contrast to previous reports, it is deduced that Nb intercalation in Bi<sub>2</sub>Se<sub>3</sub>does not take place. Instead, the superconducting behaviour in samples of nominal composition Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>results from the (BiSe)<sub>1.10</sub>NbSe<sub>2</sub>misfit phase that is present in the sample as an impurity phase for small<italic>x</italic>(0.01 ≤ <italic>x</italic> ≤ 0.10) and as a main phase for large<italic>x</italic>(<italic>x</italic> = 0.50). The structure of this misfit phase is studied in detail using a combination of X-ray diffraction and transmission electron microscopy techniques. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000610580800001 | Publication Date | 2020-11-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2662-4443 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | OpenAccess | ||
Notes | M.E.K. was supported by the Netherlands Organisation for Scientific Research (NWO, grant code 019.181EN.003). We also acknowledge support from the EPSRC (EP/ R042594/1, EP/P018874/1, EP/M020517/1) and the Leverhulme Trust (RPG-2018-377). J.H. acknowledges support from the University of Antwerp through BOF Grant No. 31445. We thank DLS Ltd for beam time (EE18786), Dr Clare Murray for assistance on I11 and Dr Jon Wade from the Department of Earth Sciences, University of Oxford for performing the SEM measurements. We also thank Dr Michal Dušak and Dr Václav Petřiček for their advice concerning the use of the Jana2006 software. | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:176116 | Serial | 6705 | ||
Permanent link to this record | |||||
Author | Vandemeulebroucke, D.; Batuk, M.; Hajizadeh, A.; Wastiaux, M.; Roussel, P.; Hadermann, J. | ||||
Title | Incommensurate Modulations and Perovskite Growth in LaxSr2–xMnO4−δAffecting Solid Oxide Fuel Cell Conductivity | Type | A1 Journal Article | ||
Year | 2024 | Publication | Chemistry of Materials | Abbreviated Journal ![]() |
Chem. Mater. |
Volume | Issue | Pages | |||
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Ruddlesden-Popper La????Sr2−????MnO4−???? materials are interesting symmetric solid oxide fuel cell electrodes due to their good redox stability, mixed ionic and electronic conducting behavior and thermal expansion that matches well with common electrolytes. In reducing environments – as at a solid oxide fuel cell anode – the x = 0.5 member, i.e. La0.5Sr1.5MnO4−????, has a much higher total conductivity than compounds with a different La/Sr ratio, although all those compositions have the same K2NiF4-type I4/mmm structure. The origin for this conductivity difference is not yet known in literature. Now, a combination of in-situ and ex-situ 3D electron diffraction, high-resolution imaging, energy-dispersive X-ray analysis and electron energy-loss spectroscopy uncovered clear differences between x=0.25 and x=0.5 in the pristine structure, as well as in the transformations upon high-temperature reduction. In La0.5Sr1.5MnO4−????, Ruddlesden-Popper n=2 layer defects and an amorphous surface layer are present, but not in La0.25Sr1.75MnO4−????. After annealing at 700°C in 5% H2/Ar, La0.25Sr1.75MnO4−???? transforms to a tetragonal 2D incommensurately modulated structure with modulation vectors ⃗????1 = 0.2848(1) · (⃗????* +⃗????*) and ⃗????2 =0.2848(1) · (⃗????* – ⃗????*), whereas La0.5Sr1.5MnO4−???? only partially transforms to an orthorhombic 1D incommensurately modulated structure, with ⃗???? = 0.318(2) · ⃗????*. Perovskite domains grow at the crystal edge at 700°C in 5% H2 or vacuum, due to the higher La concentration on the surface compared to the bulk, which leads to a different thermodynamic equilibrium. Since it is known that a lower degree of oxygen vacancy ordering and a higher amount of perovskite blocks enhance oxygen mobility, those differences in defect structure and structural transformation upon reduction, might all contribute to the higher conductivity of La0.5Sr1.5MnO4−???? in solid oxide fuel cell anode conditions compared to other La/Sr ratios. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 001174840900001 | Publication Date | 2024-02-20 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.6 | Times cited | Open Access | Not_Open_Access | |
Notes | Universiteit Antwerpen, BOF TOP 38689 ; Fonds Wetenschappelijk Onderzoek, I003218N ; European Commission NanED, 956099 ; | Approved | Most recent IF: 8.6; 2024 IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:204354 | Serial | 8997 | ||
Permanent link to this record | |||||
Author | Batuk, M.; Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Sheptyakov, D.V.; Frontzek, M.; Hadermann, J.; Abakumov, A.M. | ||||
Title | Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemistry of materials | Abbreviated Journal ![]() |
Chem Mater |
Volume | 27 | Issue | 27 | Pages | 2946-2956 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000353865800028 | Publication Date | 2015-03-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 11 | Open Access | |
Notes | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | |||
Call Number | c:irua:126060 | Serial | 1807 | ||
Permanent link to this record | |||||
Author | Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J. | ||||
Title | Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 | Type | A1 Journal article | ||
Year | 2017 | Publication | Chemistry of materials | Abbreviated Journal ![]() |
Chem Mater |
Volume | 29 | Issue | 20 | Pages | 8811-8823 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000413884900028 | Publication Date | 2017-10-24 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 7 | Open Access | Not_Open_Access |
Notes | This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. | Approved | Most recent IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:147241 | Serial | 4768 | ||
Permanent link to this record | |||||
Author | Buffière, M.; Brammertz, G.; Batuk, M.; Verbist, C.; Mangin, D.; Koble, C.; Hadermann, J.; Meuris, M.; Poortmans, J. | ||||
Title | Microstructural analysis of 9.7% efficient Cu2ZnSnSe4 thin film solar cells | Type | A1 Journal article | ||
Year | 2014 | Publication | Applied physics letters | Abbreviated Journal ![]() |
Appl Phys Lett |
Volume | 105 | Issue | 18 | Pages | 183903 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | This work presents a detailed analysis of the microstructure and the composition of our record Cu 2ZnSnSe4 (CZTSe)-CdS-ZnO solar cell with a total area efficiency of 9.7%. The average composition of the CZTSe crystallites is Cu 1.94 Zn 1.12Sn0.95Se3.99. Large crystals of ZnSe secondary phase (up to 400 nm diameter) are observed at the voids between the absorber and the back contact, while smaller ZnSe domains are segregated at the grain boundaries and close to the surface of the CZTSe grains. An underlying layer and some particles of Cu xSe are observed at the Mo-MoSe2-Cu2ZnSnSe4 interface. The free surface of the voids at the back interface is covered by an amorphous layer containing Cu, S, O, and C, while the presence of Cd, Na, and K is also observed in this region. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000345000000086 | Publication Date | 2014-11-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951;1077-3118; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 17 | Open Access | |
Notes | Approved | Most recent IF: 3.411; 2014 IF: 3.302 | |||
Call Number | UA @ lucian @ c:irua:121329 | Serial | 2038 | ||
Permanent link to this record | |||||
Author | Turner, S.; Egoavil, R.; Batuk, M.; Abakumov, A.A.; Hadermann, J.; Verbeeck, J.; Van Tendeloo, G. | ||||
Title | Site-specific mapping of transition metal oxygen coordination in complex oxides | Type | A1 Journal article | ||
Year | 2012 | Publication | Applied physics letters | Abbreviated Journal ![]() |
Appl Phys Lett |
Volume | 101 | Issue | 24 | Pages | 241910 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We demonstrate site-specific mapping of the oxygen coordination number for transition metals in complex oxides using atomically resolved electron energy-loss spectroscopy in an aberration-corrected scanning transmission electron microscope. Pb2Sr2Bi2Fe6O16 contains iron with a constant Fe3+ valency in both octahedral and tetragonal pyramidal coordination and is selected to demonstrate the principle of site-specific coordination mapping. Analysis of the site-specific Fe-L2,3 data reveals distinct variations in the fine structure that are attributed to Fe in a six-fold (octahedron) or five-fold (distorted tetragonal pyramid) oxygen coordination. Using these variations, atomic resolution coordination maps are generated that are in excellent agreement with simulations. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000312490000035 | Publication Date | 2012-12-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-6951; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.411 | Times cited | 12 | Open Access | |
Notes | Fwo; Countatoms; Vortex; Esteem 312483; esteem2jra3 ECASJO; | Approved | Most recent IF: 3.411; 2012 IF: 3.794 | ||
Call Number | UA @ lucian @ c:irua:105302UA @ admin @ c:irua:105302 | Serial | 3030 | ||
Permanent link to this record | |||||
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 | ||
Permanent link to this record | |||||
Author | Gvozdetskyi, V.; Bhaskar, G.; Batuk, M.; Zhao, X.; Wang, R.; Carnahan, S.L.; Hanrahan, M.P.; Ribeiro, R.A.; Canfield, P.C.; Rossini, A.J.; Wang, C.-Z.; Ho, K.-M.; Hadermann, J.; Zaikina, J.V. | ||||
Title | Computationally Driven Discovery of a Family of Layered LiNiB Polymorphs | Type | A1 Journal article | ||
Year | 2019 | Publication | Angewandte Chemie: international edition in English | Abbreviated Journal ![]() |
Angew Chem Int Edit |
Volume | 58 | Issue | 44 | Pages | 15855-15862 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Two novel lithium nickel boride polymorphs RT-LiNiB and HT-LiNiB with layered crystal structures are reported. This family of compounds was theoretically predicted by using the adaptive genetic algorithm (AGA) and subsequently synthesized via a hydride route with LiH precursor as a lithium source. Being unique among the known ternary transition metal borides, the LiNiB structures feature Li layers alternating with nearly planar [NiB] layers, composed of Ni hexagonal rings centered by B-B pairs. A comprehensive study using a combination of single crystal/synchrotron powder X-ray diffraction data, solid-state 7Li and 11B NMR, scanning transmission electron microscopy, quantum chemistry calculations, and magnetism has shed light on the intrinsic features of these polymorphic compounds. The unique layered structures of LiNiB compounds make them ultimate precursors to further study their exfoliation, paving a way toward two-dimensional transition metal borides, MBenes. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000491219600038 | Publication Date | 2019-10-28 | |
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 | Open Access | ||
Notes | the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant GBMF4411. The Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under contract #DE-AC02-07CH11358. 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. | Approved | Most recent IF: 11.994 | ||
Call Number | EMAT @ emat @c:irua:164752 | Serial | 5433 | ||
Permanent link to this record | |||||
Author | Zaghi, A.E.; Buffière, M.; Brammertz, G.; Batuk, M.; Lenaers, N.; Kniknie, B.; Hadermann, J.; Meuris, M.; Poortmans, J.; Vleugels, J. | ||||
Title | Mechanical synthesis of high purity Cu-In-Se alloy nanopowder as precursor for printed CISe thin film solar cells | Type | A1 Journal article | ||
Year | 2014 | Publication | Advanced powder technology | Abbreviated Journal ![]() |
Adv Powder Technol |
Volume | 25 | Issue | 4 | Pages | 1254-1261 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Mechanical alloying and ball milling are low cost, up-scalable techniques for the preparation of high purity chalcogenide nanopowders to be used as precursor material for printing thin film solar cells. In this study, high purity copper indium selenium (Cu-In-Se) alloy nanopowders with 20-200 nm particle size were synthesized from macroscopic elemental Cu, In and Se powders via mechanical alloying and planetary ball milling. The particle size distribution, morphology, composition, and purity level of the synthesized Cu-In-Se alloy nanopowders were investigated. Thin Cu-In-Se alloy nanopowder ink coatings, deposited on Mo-coated glass substrates by doctor blading, were converted into a CuInSe2 semiconductor film by selenization heat treatment in Se vapor. The CuInSe2 film showed semiconducting band gap around 1 eV measured by photoluminescence spectroscopy. CuInSe2 absorber layer based thin film solar cell devices were fabricated to assess their performance. The solar cell device showed a total efficiency of 4.8%, as measured on 0.25 cm(2) area cell. (c) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Zeist | Editor | ||
Language | Wos | 000341871700015 | Publication Date | 2014-03-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0921-8831; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.659 | Times cited | 10 | Open Access | |
Notes | Approved | Most recent IF: 2.659; 2014 IF: 2.638 | |||
Call Number | UA @ lucian @ c:irua:119896 | Serial | 1977 | ||
Permanent link to this record | |||||
Author | Zhang, F.; Batuk, M.; Hadermann, J.; Manfredi, G.; Mariën, A.; Vanmeensel, K.; Inokoshi, M.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
Title | Effect of cation dopant radius on the hydrothermal stability of tetragonal zirconia: Grain boundary segregation and oxygen vacancy annihilation | Type | A1 Journal article | ||
Year | 2016 | Publication | Acta materialia | Abbreviated Journal ![]() |
Acta Mater |
Volume | 106 | Issue | 106 | Pages | 48-58 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The hydrothermal aging stability of 3Y-TZP-xM2O3 (M = La, Nd, Sc) was investigated as a function of 0.02–5 mol% M2O3 dopant content and correlated to the overall phase content, t-ZrO2 lattice parameters, grain size distribution, grain boundary chemistry and ionic conductivity. The increased aging stability with increasing Sc2O3 content and the optimum content of 0.4–0.6 mol% Nd2O3 or 0.2–0.4 mol% La2O3, resulting in the highest aging resistance, could be directly related to the constituent phases and the lattice parameters of the remaining tetragonal zirconia. At low M2O3 dopant contents ≤0.4 mol%, the different aging behavior of tetragonal zirconia was attributed to the defect structure of the zirconia grain boundary which was influenced by the dopant cation radius. It was observed that the grain boundary ionic resistivity and the aging resistance followed the same trend: La3+ > Nd3+ > Al3+ > Sc3+, proving that hydrothermal aging is driven by the diffusion of water-derived mobile species through the oxygen vacancies. Accordingly, we elucidated the underlying mechanism by which a larger trivalent cation segregating at the zirconia grain boundary resulted in a higher aging resistance. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000371650300006 | Publication Date | 2016-01-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1359-6454 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 5.301 | Times cited | 37 | Open Access | |
Notes | The authors acknowledge the Research Fund of KU Leuven under project 0T/10/052 and the Fund for Scientific Research Flanders (FWO-Vlaanderen) under grant G.0431.10N. F. Zhang thanks the Research Fund of KU Leuven for her post-doctoral fellowship (PDM/15/153). | Approved | Most recent IF: 5.301 | ||
Call Number | c:irua:132435 | Serial | 4076 | ||
Permanent link to this record |