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| Author | Volykhov, A.A.; Sanchez-Barriga, J.; Batuk, M.; Callaert, C.; Hadermann, J.; Sirotina, A.P.; Neudachina, V.S.; Belova, A.I.; Vladimirova, N.V.; Tamm, M.E.; Khmelevsky, N.O.; Escudero, C.; Perez-Dieste, V.; Knop-Gericke, A.; Yashina, L.V. | ||||
| Title | Can surface reactivity of mixed crystals be predicted from their counterparts? A case study of (Bi1-xSbx)2Te3 topological insulators | Type | A1 Journal article | ||
| Year | 2018 | Publication | Journal of materials chemistry C : materials for optical and electronic devices | Abbreviated Journal | J Mater Chem C |
| Volume | 6 | Issue | 33 | Pages | 8941-8949 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract  |
The behavior of ternary mixed crystals or solid solutions and its correlation with the properties of their binary constituents is of fundamental interest. Due to their unique potential for application in future information technology, mixed crystals of topological insulators with the spin-locked, gapless states on their surfaces attract huge attention of physicists, chemists and material scientists. (Bi1-xSbx)(2)Te-3 solid solutions are among the best candidates for spintronic applications since the bulk carrier concentration can be tuned by varying x to obtain truly bulk-insulating samples, where the topological surface states largely contribute to the transport and the realization of the surface quantum Hall effect. As this ternary compound will be evidently used in the form of thin-film devices its chemical stability is an important practical issue. Based on the atomic resolution HAADF-TEM and EDX data together with the XPS results obtained both ex situ and in situ, we propose an atomistic picture of the mixed crystal reactivity compared to that of its binary constituents. We find that the surface reactivity is determined by the probability of oxygen attack on the Te-Sb bonds, which is directly proportional to the number of Te atoms bonded to at least one Sb atom. The oxidation mechanism includes formation of an amorphous antimony oxide at the very surface due to Sb diffusion from the first two quintuple layers, electron tunneling from the Fermi level of the crystal to oxygen, oxygen ion diffusion to the crystal, and finally, slow Te oxidation to the +4 oxidation state. The oxide layer thickness is limited by the electron transport, and the overall process resembles the Cabrera-Mott mechanism in metals. These observations are critical not only for current understanding of the chemical reactivity of complex crystals, but also to improve the performance of future spintronic devices based on topological materials. | ||||
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| Language | Wos | 000443279300007 | Publication Date | 2018-07-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2050-7526; 2050-7534 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 5.256 | Times cited | 3 | Open Access | Not_Open_Access |
| Notes | ; The authors acknowledge financial support within the bilateral program "Russian-German Laboratory at BESSY II''. We thank Helmholtz-Zentrum Berlin for granting access to the beamlines RGBL, UE112-PGM2a and ISISS. Support of ALBA staff during measurements at the CIRCE beamline is gratefully acknowledged. We thank Dr Ivan Bobrikov for support in the XRD measurements and Daria Tsukanova for the participation in crystal preparation and XPS measurements. A. Volykhov thanks RSF (grant 18-73-00248) for financial support. A. I. Belova acknowledges support from the G-RISC Centre of Excellence. The work was supported by Helmholtz Gemeinschaft (Grant No. HRJRG-408) and RFBR (grant 14-03-31518). J. H. and C. C. acknowledge support from the University of Antwerp through the BOF grant 31445. ; | Approved | Most recent IF: 5.256 | ||
| Call Number | UA @ lucian @ c:irua:153647 | Serial | 5080 | ||
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| Author | Gamon, J.; Bassat, J.-M.; Villesuzanne, A.; Duttine, M.; Batuk, M.; Vandemeulebroucke, D.; Hadermann, J.; Alassani, F.; Weill, F.; Durand, E.; Demourgues, A. | ||||
| Title | Impact of anionic ordering on the iron site distribution and valence states in oxyfluoride Sr2FeO3+xF1-x(x=0.08, 0.2) with a layered Perovskite network | Type | A1 Journal article | ||
| Year | 2023 | Publication | Inorganic chemistry | Abbreviated Journal | |
| Volume | 62 | Issue | 27 | Pages | 10822-10832 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Sr2FeO3+x F1-x (x = 0.08, 0.2), an n = 1 Ruddlesden-Popperphase, was synthesized from the oxidationof Sr2FeO3F in air at high temperature followinga fluorine for oxygen substitution and Fe3+ to Fe4+ oxidation. A structural investigation of both compounds was performedusing complementary and high-resolution techniques (Synchrotron X-rayand electron diffraction, Mo''ssbauer spectroscopy, HR-STEM)coupled to DFT calculation. This study reveals that oxidation leadsto a high degree of apical anion disorder coupled to antiphase boundaries. Sr2FeO3F, an oxyfluoride compoundwith an n = 1 Ruddlesden-Popper structure,was identifiedas a potential interesting mixed ionic and electronic conductor (MIEC).The phase can be synthesized under a range of different pO(2) atmospheres, leading to various degrees of fluorinefor oxygen substitution and Fe4+ content. A structuralinvestigation and thorough comparison of both argon- and air-synthesizedcompounds were performed by combining high-resolution X-ray and electrondiffraction, high-resolution scanning transmission electron microscopy,Mo''ssbauer spectroscopy, and DFT calculations. While the argon-synthesizedphase shows a well-behaved O/F ordered structure, this study revealedthat oxidation leads to averaged large-scale anionic disorder on theapical site. In the more oxidized Sr2FeO3.2F0.8 oxyfluoride, containing 20% of Fe4+, two differentFe positions can be identified with a 32%/68% occupancy (P4/nmm space group). This originates due to the presenceof antiphase boundaries between ordered domains within the grains.Relations between site distortion and valence states as well as stabilityof apical anionic sites (O vs F) are discussed. This study paves theway for further studies on both ionic and electronic transport propertiesof Sr2FeO3.2F0.8 and its use in MIEC-baseddevices, such as solid oxide fuel cells. | ||||
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| Language | Wos | 001018974700001 | Publication Date | 2023-06-29 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 4.6 | Times cited | Open Access | Not_Open_Access | |
| Notes | Approved | Most recent IF: 4.6; 2023 IF: 4.857 | |||
| Call Number | UA @ admin @ c:irua:197789 | Serial | 8881 | ||
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| 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. | ||||
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| 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 | ||
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| Author | Mallick, S.; Khalsa, G.; Kaaret, J.Z.; Zhang, W.; Batuk, M.; Gibbs, A.S.; Hadermann, J.; Halasyamani, P.S.; Benedek, N.A.; Hayward, M.A. | ||||
| Title | The influence of the 6s² configuration of Bi³+ on the structures of A ' BiNb₂O₇ (A ' = Rb, Na, Li) layered perovskite oxides | Type | A1 Journal article | ||
| Year | 2021 | Publication | Journal of the Chemical Society : Dalton transactions | Abbreviated Journal | |
| Volume | 50 | Issue | 42 | Pages | 15359-15369 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The 'hybrid improper' mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7 and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+ cations which are often observed to stabilize acentric crystal structures due to their 6s(2) electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7 and LiBiNb2O7 adopt polar crystal structures (space groups I2cm and B2cm respectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+ cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+ cations with Nd3+ cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7 (space group P2(1)2(1)2(1)) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+ cations. | ||||
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| Language | Wos | 000706651100001 | Publication Date | 2021-10-05 | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1477-9234 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access | OpenAccess | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | UA @ admin @ c:irua:182584 | Serial | 6893 | ||
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| Author | Bez, R.; Zehani, K.; Batuk, M.; Van Tendeloo, G.; Mliki, N.; Bessais, L. | ||||
| Title | Structure and magnetic properties of Sm(Fe,Si)(9)C/alpha-Fe nanocomposite magnets | Type | A1 Journal article | ||
| Year | 2017 | Publication | Journal of alloys and compounds | Abbreviated Journal | J Alloy Compd |
| Volume | 695 | Issue | 695 | Pages | 810-817 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
SmFe8.75 Si-0.25 C/alpha-Fe nanocomposites have been successfully synthesized using high energy milling, followed by annealing at 750 degrees C. The crystal structure of these compounds was characterized by the Rietveld method using powder X-ray diffraction data. By increasing the concentration of Sm, we observed a decrease in the amount of alpha-Fe phase. The morphology of the samples was determined by scanning and transmission electron microscopy. The average grain size is about 20 nm. The magnetic properties were investigated at room temperature and at 10 K. A ferromagnetic behavior was observed in all samples at both temperatures. An increase of the soft magnetic phase alpha-Fe induced an increase in the magnetization and a decrease in coercivity. (C) 2016 Elsevier B.V. All rights reserved. | ||||
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| Publisher | Place of Publication | Amsterdam | Editor | ||
| Language | Wos | 000391817600098 | Publication Date | 2016-10-19 | |
| 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 | 1 | Open Access | Not_Open_Access |
| Notes | ; This work is main supported by the CNRS and the “Ministere de l'Enseignement Superieur, de la Recherche Scientifique” (LR99ES17) (Tunisia), PHC-Utique (Project 11/G 1301) and PHC-Maghreb (Project 15MAG07). The authors acknowledge the French SIE doctoral school of the University Paris Est for its support. ; | Approved | Most recent IF: 3.133 | ||
| Call Number | UA @ lucian @ c:irua:140380 | Serial | 4448 | ||
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| 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. |
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| Language | English | Wos | 001174840900001 | Publication Date | 2024-02-20 |
| Series Editor | Series Title | Abbreviated Series Title | |||
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| 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 | ||
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| 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. | ||||
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| 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 | ||
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| Author | Palgrave, R.G.; Borisov, P.; Dyer, M.S.; McMitchell, S.R.C.; Darling, G.R.; Claridge, J.B.; Batuk, M.; Tan, H.; Tian, H.; Verbeeck, J.; Hadermann, J.; Rosseinsky, M.J.; | ||||
| Title | Artificial construction of the layered Ruddlesden-Popper manganite La2Sr2Mn3O10 by reflection high energy electron diffraction monitored pulsed laser deposition | Type | A1 Journal article | ||
| Year | 2012 | Publication | Journal of the American Chemical Society | Abbreviated Journal | J Am Chem Soc |
| Volume | 134 | Issue | 18 | Pages | 7700-7714 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Pulsed laser deposition has been used to artificially construct the n = 3 Ruddlesden Popper structure La2Sr2Mn3O10 in epitaxial thin film form by sequentially layering La1-xSrxMnO3 and SrO unit cells aided by in situ reflection high energy electron diffraction monitoring. The interval deposition technique was used to promote two-dimensional SrO growth. X-ray diffraction and cross-sectional transmission electron microscopy indicated that the trilayer structure had been formed. A site ordering was found to differ from that expected thermodynamically, with the smaller Sr2+ predominantly on the R site due to kinetic trapping of the deposited cation sequence. A dependence of the out-of-plane lattice parameter on growth pressure was interpreted as changing the oxygen content of the films. Magnetic and transport measurements on fully oxygenated films indicated a frustrated magnetic ground state characterized as a spin glass-like magnetic phase with the glass temperature T-g approximate to 34 K. The magnetic frustration has a clear in-plane (ab) magnetic anisotropy, which is maintained up to temperatures of 150 K. Density functional theory calculations suggest competing antiferromagnetic and ferromagnetic long-range orders, which are proposed as the origin of the low-temperature glassy state. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000303696200029 | Publication Date | 2012-03-30 | |
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| ISSN | 0002-7863;1520-5126; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 13.858 | Times cited | 27 | Open Access | |
| Notes | Fwo; Esteem 026019 | Approved | Most recent IF: 13.858; 2012 IF: 10.677 | ||
| Call Number | UA @ lucian @ c:irua:98947UA @ admin @ c:irua:98947 | Serial | 153 | ||
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| Author | Buffière, M.; Zaghi, A.E.; Lenaers, N.; Batuk, M.; Khelifi, S.; Drijkoningen, J.; Hamon, J.; Stesmans, A.; Kepa, J.; Afanas’ev, V.V.; Hadermann, J.; D’Haen, J.; Manca, J.; Vleugels, J.; Meuris, M.; Poortmans, J.; | ||||
| Title | Effect of binder content in Cu-In-Se precursor ink on the physical and electrical properties of printed CuInSe2 solar cells | Type | A1 Journal article | ||
| Year | 2014 | Publication | The journal of physical chemistry: C : nanomaterials and interfaces | Abbreviated Journal | J Phys Chem C |
| Volume | 118 | Issue | 47 | Pages | 27201-27209 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Printed chalcopyrite thin films have attracted considerable attention in recent years due to their potential in the high-throughput production of photovoltaic devices. To improve the homogeneity of printed CuInSe2 (CISe) layers, chemical additives such as binder can be added to the precursor ink. In this contribution, we investigate the influence of the dicyandiamide (DCDA) content, used as a binder in the precursor ink, on the physical and electrical properties of printed CISe solar cells. It is shown that the use of the binder leads to a dense absorber, composed of large CISe grains close to the surface, while the bulk of the layer consists of CISe crystallites embedded in a CuxS particle based matrix, resulting from the limited sintering of the precursor in this region. The expected additional carbon contamination of the CISe layer due to the addition of the binder appears to be limited, and the optical properties of the CISe layer are similar to the reference sample without additive. The electrical characterization of the corresponding CISe/CdS solar cells shows a degradation of the efficiency of the devices, due to a modification in the predominant recombination mechanisms and a limitation of the space charge region width when using the binder; both effects could be explained by the inhomogeneity of the bulk of the CISe absorber and high defect density at the CISe/CuxS-based matrix interface. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000345722400003 | Publication Date | 2014-11-06 | |
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| ISSN | 1932-7447;1932-7455; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.536 | Times cited | 4 | Open Access | |
| Notes | Approved | Most recent IF: 4.536; 2014 IF: 4.772 | |||
| Call Number | UA @ lucian @ c:irua:121332 | Serial | 801 | ||
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| Author | E. Zaghi, A.; Buffière, M.; Koo, J.; Brammertz, G.; Batuk, M.; Verbist, C.; Hadermann, J.; Kim, W.K.; Meuris, M.; Poortmans, J.; Vleugels, J.; | ||||
| Title | Effect of selenium content of CuInSex alloy nanopowder precursors on recrystallization of printed CuInSe2 absorber layers during selenization heat treatment | Type | A1 Journal article | ||
| Year | 2014 | Publication | Thin solid films : an international journal on the science and technology of thin and thick films | Abbreviated Journal | Thin Solid Films |
| Volume | Issue | Pages | 1-7 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Polycrystalline CuInSe2 semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe2 semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSex (x = 2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe2 phase during the selenization process was investigated. The nanostructure and phase variation of CuInSex nanopowders were investigated by different characterization techniques. The recrystallization process of the 12 μm thick CuInSex coatings into the CuInSe2 phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSex precursors with lower selenium content showed a more pronounced phase conversion into CuInSe2 compared to the higher selenium content CuInSex precursors. Moreover, the CuInSex (x = 0.5 and 1) precursor resulted in a denser polycrystalline CuInSe2 semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSex precursor system compared to a CuInSe2 phase precursor, and the formation of intermediate CuSe and CuSe2 fluxing phases during selenization. | ||||
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| Publisher | Place of Publication | Lausanne | Editor | ||
| Language | Wos | 000352225900004 | Publication Date | 2014-10-13 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0040-6090; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 1.879 | Times cited | 7 | Open Access | |
| Notes | Approved | Most recent IF: 1.879; 2014 IF: 1.759 | |||
| Call Number | c:irua:121330 | Serial | 834 | ||
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| Author | Batuk, M.; Tyablikov, O.A.; Tsirlin, A.A.; Kazakov, S.M.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Antipov, E.V.; Abakumov, A.M.; Hadermann, J. | ||||
| Title | Structure and magnetic properties of a new anion-deficient perovskite Pb2Ba2BiFe4ScO13 with crystallographic shear structure | Type | A1 Journal article | ||
| Year | 2013 | Publication | Materials research bulletin | Abbreviated Journal | Mater Res Bull |
| Volume | 48 | Issue | 9 | Pages | 3459-3465 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Pb2Ba2BiFe4ScO13, a new n = 5 member of the oxygen-deficient perovskite-based A(n)B(n)O(3n-2) homologous series, was synthesized using a solid-state method. The crystal structure of Pb2Ba2BiFe4ScO13 was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mossbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) angstrom, b = 4.0426(1) angstrom, and c=27.3435(1) angstrom. In the Pb2Ba2BiFe4ScO13 structure, quasi-two-dimensional perovskite blocks are periodically interleaved with 1/2[1 1 0] ((1) over bar 0 1)(p) crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO6 octahedra are transformed into chains of edge-sharing FeO5 distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe3+ and Sc3+. The chains of the FeO5 pyramids and (Fe,Sc)O-6 octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb2+). The remaining A-cations (Bi3+, Ba2+) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb2Ba2BiFe4ScO13 is antiferromagnetically ordered below T-N approximate to 350 K. (C) 2013 Elsevier Ltd. All rights reserved. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | New York, N.Y. | Editor | ||
| Language | Wos | 000322354000076 | Publication Date | 2013-05-17 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0025-5408; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.446 | Times cited | 2 | Open Access | |
| Notes | Approved | Most recent IF: 2.446; 2013 IF: 1.968 | |||
| Call Number | UA @ lucian @ c:irua:109756 | Serial | 3282 | ||
| Permanent link to this record | |||||
| Author | Korneychik, O.E.; Batuk, M.; Abakumov, A.M.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Pokholok, K.V.; Filimonov, D.S.; Antipov, E.V. | ||||
| Title | Pb2.85Ba2.15Fe4SnO13 : a new member of the AnBnO3n-2 anion-deficient perovskite-based homologous series | Type | A1 Journal article | ||
| Year | 2011 | Publication | Journal of solid state chemistry | Abbreviated Journal | J Solid State Chem |
| Volume | 184 | Issue | 12 | Pages | 3150-3157 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Pb2.85Ba2.15Fe4SnO13, a new n=5 member of the anion-deficient perovskite based AnBnO3n−2 (A=Pb, Ba, B=Fe, Sn) homologous series, was synthesized by the solid state method. The crystal structure of Pb2.85Ba2.15Fe4SnO13 was investigated using a combination of neutron powder diffraction, electron diffraction, high angle annular dark field scanning transmission electron microscopy and Mössbauer spectroscopy. It crystallizes in the Ammm space group with unit cell parameters a=5.7990(1) Å, b=4.04293(7) Å and c=26.9561(5) Å. The Pb2.85Ba2.15Fe4SnO13 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110](1̄01)p crystallographic shear (CS) planes. The corner-sharing FeO6 octahedra at the CS planes are transformed into edge-sharing FeO5 distorted tetragonal pyramids. The octahedral positions in the perovskite blocks between the CS planes are jointly taken up by Fe and Sn, with a preference of Sn towards the position at the center of the perovskite block. The chains of FeO5 pyramids and (Fe,Sn)O6 octahedra of the perovskite blocks delimit six-sided tunnels at the CS planes occupied by double chains of Pb atoms. The compound is antiferromagnetically ordered below TN=368±15 K. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000297662500003 | Publication Date | 2011-09-30 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4596; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.299 | Times cited | 7 | Open Access | |
| Notes | Approved | Most recent IF: 2.299; 2011 IF: 2.159 | |||
| Call Number | UA @ lucian @ c:irua:94013 | Serial | 3550 | ||
| Permanent link to this record | |||||
| 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 | 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 | 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. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000353865800028 | Publication Date | 2015-03-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0897-4756;1520-5002; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 9.466 | Times cited | 11 | Open Access | |
| Notes | Approved | Most recent IF: 9.466; 2015 IF: 8.354 | |||
| Call Number | c:irua:126060 | Serial | 1807 | ||
| Permanent link to this record | |||||
| Author | Chizhov, A.; Vasiliev, R.; Rumyantseva, M.; Krylov, I.; Drozdov, K.; Batuk, M.; Hadermann, J.; Abakumov, A.; Gaskov, A. | ||||
| Title | Light-activated sub-ppm NO2 detection by hybrid ZnO/QD nanomaterials vs. charge localization in core-shell QD | Type | A1 Journal article | ||
| Year | 2019 | Publication | Frontiers in materials | Abbreviated Journal | |
| Volume | 6 | Issue | 6 | Pages | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
New hybrid materials-photosensitized nanocomposites containing nanocrystal heterostructures with spatial charge separation, show high response for practically important sub-ppm level NO2 detection at room temperature. Nanocomposites ZnO/CdSe, ZnO/(CdS@CdSe), and ZnO/(ZnSe@CdS) were obtained by the immobilization of nanocrystals-colloidal quantum dots (QDs), on the matrix of nanocrystalline ZnO. The formation of crystalline core-shell structure of QDs was confirmed by HAADF-STEM coupled with EELS mapping. Optical properties of photosensitizers have been investigated by optical absorption and luminescence spectroscopy combined with spectral dependences of photoconductivity, which proved different charge localization regimes. Photoelectrical and gas sensor properties of nanocomposites have been studied at room temperature under green light (max = 535 nm) illumination in the presence of 0.12-2 ppm NO2 in air. It has been demonstrated that sensitization with type II heterostructure ZnSe@CdS with staggered gap provides the rapid growth of effective photoresponse with the increase in the NO2 concentration in air and the highest sensor sensitivity toward NO2. We believe that the use of core-shell QDs with spatial charge separation opens new possibilities in the development of light-activated gas sensors working without thermal heating. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000487641600002 | Publication Date | 2019-09-24 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2296-8016 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | 1 | Open Access | ||
| Notes | ; This work was financially supported by RFBR grant No. 1653-76001 (RFBR – ERA.Net FONSENS 096) and in part by a grant from the St. Petersburg State University – Event 3-2018 (id: 26520408). AC acknowledges support from the RFBR grant No. 18-33-01004. ; | Approved | Most recent IF: NA | ||
| Call Number | UA @ admin @ c:irua:163776 | Serial | 5390 | ||
| Permanent link to this record | |||||
| Author | Marikutsa, A.; Yang, L.; Rumyantseva, M.; Batuk, M.; Hadermann, J.; Gaskov, A. | ||||
| Title | Sensitivity of nanocrystalline tungsten oxide to CO and ammonia gas determined by surface catalysts | Type | A1 Journal article | ||
| Year | 2018 | Publication | Sensors and actuators : B : chemical | Abbreviated Journal | |
| Volume | 277 | Issue | Pages | 336-346 | |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Nanocrystalline tungsten oxide with variable particle size and surface area was synthesized by aqueous deposition and heat treatment for use in resistive gas sensors. Surface modification with 1 wt.% Pd and Ru was performed by impregnation to improve the sensitivity to CO and ammonia. Acid and oxidation surface sites were evaluated by temperature-programmed techniques using probe molecules. The surface acidity dropped with increasing particle size, and was weakly affected by additives. Lower crystallinity of WO3 and the presence of Ru species favoured temperature-programmed reduction of the materials. Modifying WO3 increased its sensitivity, to CO at ambient condition for modification by Pd and to NH3 at elevated temperature for Ru modification. An in situ infrared study of the gas – solid interaction showed that the catalytic additives change the interaction route of tungsten oxide with the target gases and make the reception of detected molecules independent of the semiconductor oxide matrix. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000453066700042 | Publication Date | 2018-09-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0925-4005 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:156219 | Serial | 8513 | ||
| Permanent link to this record | |||||
| Author | Malkov, I., V; Krivetskii, V.V.; Potemkin, D., I; Zadesenets, A., V; Batuk, M.M.; Hadermann, J.; Marikutsa, A., V; Rumyantseva, M.N.; Gas'kov, A.M. | ||||
| Title | Effect of Bimetallic Pd/Pt Clusters on the Sensing Properties of Nanocrystalline SnO2 in the Detection of CO | Type | A1 Journal article | ||
| Year | 2018 | Publication | Russian journal of inorganic chemistry | Abbreviated Journal | Russ J Inorg Chem+ |
| Volume | 63 | Issue | 8 | Pages | 1007-1011 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Nanocrystalline tin dioxide modified by Pd and Pt clusters or by bimetallic PdPt nanoparticles was synthesized. Distribution of the modifers on the SnO2 surface was studied by high-resolution transmission electron microscopy and energy dispersive X-ray microanalysis with element distribution mapping. It was shown that the Pd/Pt ratio in bimetallic particles varies over a broad range and does not depend on the particle diameter. The effect of platinum metals on the reducibility of nanocrystalline SnO2 by hydrogen was determined. The sensing properties of the resulting materials towards 6.7 ppm CO in air were estimated in situ by electrical conductivity measurements. The sensor response of SnO2 modified with bimetallic PdPt particles was a superposition of the signals of samples with Pt and Pd clusters. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000442749500003 | Publication Date | 2018-08-25 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0036-0236 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 0.787 | Times cited | 3 | Open Access | Not_Open_Access |
| Notes | ; This work was supported by the ERA.Net RUS Plus program (project 096 FONSENS, RFBR grant 16-53-76001). ; | Approved | Most recent IF: 0.787 | ||
| Call Number | UA @ lucian @ c:irua:153752 | Serial | 5092 | ||
| Permanent link to this record | |||||
| Author | Naberezhnyi, D.; Rumyantseva, M.; Filatova, D.; Batuk, M.; Hadermann, J.; Baranchikov, A.; Khmelevsky, N.; Aksenenko, A.; Konstantinova, E.; Gaskov, A. | ||||
| Title | Effects of Ag additive in low temperature CO detection with In2O3 based gas sensors | Type | A1 Journal article | ||
| Year | 2018 | Publication | Nanomaterials | Abbreviated Journal | |
| Volume | 8 | Issue | 10 | Pages | 801 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Nanocomposites In2O3/Ag obtained by ultraviolet (UV) photoreduction and impregnation methods were studied as materials for CO sensors operating in the temperature range 25-250 degrees C. Nanocrystalline In2O3 and In2O3/Ag nanocomposites were characterized by X-ray diffraction (XRD), single-point Brunauer-Emmet-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with energy dispersive X-ray (EDX) mapping. The active surface sites were investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy and thermo-programmed reduction with hydrogen (TPR-H-2) method. Sensor measurements in the presence of 15 ppm CO demonstrated that UV treatment leads to a complete loss of In2O3 sensor sensitivity, while In2O3/Ag-UV nanocomposite synthesized by UV photoreduction demonstrates an increased sensor signal to CO at T < 200 degrees C. The observed high sensor response of the In2O3/Ag-UV nanocomposite at room temperature may be due to the realization of an additional mechanism of CO oxidation with participation of surface hydroxyl groups associated via hydrogen bonds. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000451174100057 | Publication Date | 2018-10-08 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2079-4991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:156335 | Serial | 7842 | ||
| Permanent link to this record | |||||
| Author | Yang, C.; Batuk, M.; Jacquet, Q.; Rousse, G.; Yin, W.; Zhang, L.; Hadermann, J.; Abakumov, A.M.; Cibin, G.; Chadwick, A.; Tarascon, J.-M.; Grimaud, A. | ||||
| Title | Revealing pH-Dependent Activities and Surface Instabilities for Ni-Based Electrocatalysts during the Oxygen Evolution Reaction | Type | A1 Journal article | ||
| Year | 2018 | Publication | ACS energy letters | Abbreviated Journal | Acs Energy Lett |
| Volume | Issue | Pages | 2884-2890 | ||
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Multiple electrochemical processes are involved at the catalyst/ electrolyte interface during the oxygen evolution reaction (OER). With the purpose of elucidating the complexity of surface dynamics upon OER, we systematically studied two Ni-based crystalline oxides (LaNiO3−δ and La2Li0.5Ni0.5O4) and compared them with the state-of-the-art Ni−Fe (oxy)- hydroxide amorphous catalyst. Electrochemical measurements such as rotating ring disk electrode (RRDE) and electrochemical quartz microbalance microscopy (EQCM) coupled with a series of physical characterizations including transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS) were conducted to unravel the exact pH effect on both the OER activity and the catalyst stability. We demonstrate that for Ni-based crystalline catalysts the rate for surface degradation depends on the pH and is greater than the rate for surface reconstruction. This behavior is unlike that for the amorphous Ni oxyhydroxide catalyst, which is found to be more stable and pH-independent. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000453805100005 | Publication Date | 2018-11-08 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2380-8195 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access | Not_Open_Access: Available from 06.11.2019 | ||
| Notes | C.Y., J.-M.T., and A.G. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC GrantProject 670116-ARPEMA. A.G. acknowledges financial support from the ANR MIDWAY (Project ID ANR-17-CE05- 0008). We acknowledge Diamond Light Source for time awarded to the Energy Materials BAG on Beamline B18, under Proposal sp12559. | Approved | Most recent IF: NA | ||
| Call Number | EMAT @ emat @c:irua:155046 | Serial | 5067 | ||
| Permanent link to this record | |||||
| Author | 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 | Ulu Okudur, F.; Batuk, M.; Hadermann, J.; Safari, M.; De Sloovere, D.; Kumar Mylavarapu, S.; Joos, B.; D'Haen, J.; Van Bael, M.K.; Hardy, A. | ||||
| Title | Solution-gel-based surface modification of LiNi0.5Mn1.5O4-δ with amorphous Li-Ti-O coating | Type | A1 Journal article | ||
| Year | 2023 | Publication | RSC advances | Abbreviated Journal | |
| Volume | 13 | Issue | 47 | Pages | 33146-33158 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
LNMO (LiNi0.5Mn1.5O4-delta) is a high-energy density positive electrode material for lithium ion batteries. Unfortunately, it suffers from capacity loss and impedance rise during cycling due to electrolyte oxidation and electrode/electrolyte interface instabilities at high operating voltages. Here, a solution-gel synthesis route was used to coat 0.5-2.5 mu m LNMO particles with amorphous Li-Ti-O (LTO) for improved Li conduction, surface structural stability and cyclability. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) analysis coupled with energy dispersive X-ray (EDX) showed Ti-rich amorphous coatings/islands or Ti-rich spinel layers on many of the LTO-modified LNMO facets, with a thickness varying from about 1 to 10 nm. The surface modification in the form of amorphous islands was mostly possible on high-energy crystal facets. Physicochemical observations were used to propose a molecular mechanism for the surface modification, combining insights from metalorganic chemistry with the crystallographic properties of LNMO. The improvements in functional properties were investigated in half cells. The cell impedance increased faster for the bare LNMO compared to amorphous LTO modified LNMO, resulting in R-ct values as high as 1247 Omega (after 1000 cycles) for bare LNMO, against 216 Omega for the modified material. At 10C, the modified material boosted a 15% increase in average discharge capacity. The improvements in electrochemical performance were attributed to the increase in electrochemically active surface area, as well as to improved HF-scavenging, resulting in the formation of protective byproducts, generating a more stable interface during prolonged cycling. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001102666700001 | Publication Date | 2023-11-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2046-2069 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 3.9 | Times cited | Open Access | ||
| Notes | Approved | Most recent IF: 3.9; 2023 IF: 3.108 | |||
| Call Number | UA @ admin @ c:irua:202091 | Serial | 9096 | ||
| Permanent link to this record | |||||
| Author | Paulus, A.; Hendrickx, M.; Mayda, S.; Batuk, M.; Reekmans, G.; von Holst, M.; Elen, K.; Abakumov, A.M.; Adriaensens, P.; Lamoen, D.; Partoens, B.; Hadermann, J.; Van Bael, M.K.; Hardy, A. | ||||
| Title | Understanding the Activation of Anionic Redox Chemistry in Ti4+-Substituted Li2MnO3as a Cathode Material for Li-Ion Batteries | Type | A1 Journal article | ||
| Year | 2023 | Publication | ACS applied energy materials | Abbreviated Journal | ACS Appl. Energy Mater. |
| Volume | 6 | Issue | 13 | Pages | 6956-6971 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
| Abstract |
Layered Li-rich oxides, demonstrating both cationic and anionic redox chemistry being used as positive electrodes for Li-ion batteries,have raised interest due to their high specific discharge capacities exceeding 250 mAh/g. However, irreversible structural transformations triggered by anionic redox chemistry result in pronounced voltagefade (i.e., lowering the specific energy by a gradual decay of discharge potential) upon extended galvanostatic cycling. Activating or suppressing oxygen anionic redox through structural stabilization induced by redox-inactivecation substitution is a well-known strategy. However, less emphasishas been put on the correlation between substitution degree and theactivation/suppression of the anionic redox. In this work, Ti4+-substituted Li2MnO3 was synthesizedvia a facile solution-gel method. Ti4+ is selected as adopant as it contains no partially filled d-orbitals. Our study revealedthat the layered “honeycomb-ordered” C2/m structure is preserved when increasing the Ticontent to x = 0.2 in the Li2Mn1-x Ti (x) O-3 solidsolution, as shown by electron diffraction and aberration-correctedscanning transmission electron microscopy. Galvanostatic cycling hintsat a delayed oxygen release, due to an improved reversibility of theanionic redox, during the first 10 charge-discharge cyclesfor the x = 0.2 composition compared to the parentmaterial (x = 0), followed by pronounced oxygen redoxactivity afterward. The latter originates from a low activation energybarrier toward O-O dimer formation and Mn migration in Li2Mn0.8Ti0.2O3, as deducedfrom first-principles molecular dynamics (MD) simulations for the“charged” state. Upon lowering the Ti substitution to x = 0.05, the structural stability was drastically improvedbased on our MD analysis, stressing the importance of carefully optimizingthe substitution degree to achieve the best electrochemical performance. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001018266700001 | Publication Date | 2023-07-10 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2574-0962 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.4 | Times cited | Open Access | Not_Open_Access: Available from 24.12.2023 | |
| Notes | Universiteit Hasselt, AUHL/15/2 – GOH3816N ; Russian Science Foundation, 20-43-01012 ; Fonds Wetenschappelijk Onderzoek, AUHL/15/2 – GOH3816N G040116N ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO Vlaanderen and the Flemish Government-department EWI. | Approved | Most recent IF: 6.4; 2023 IF: NA | ||
| Call Number | EMAT @ emat @c:irua:198160 | Serial | 8809 | ||
| Permanent link to this record | |||||
| Author | Zhang, F.; Vanmeensel, K.; Batuk, M.; Hadermann, J.; Inokoshi, M.; Van Meerbeek, B.; Naert, I.; Vleugels, J. | ||||
| Title | Highly-translucent, strong and aging-resistant 3Y-TZP ceramics for dental restoration by grain boundary segregation | Type | A1 Journal article | ||
| Year | 2015 | Publication | Acta biomaterialia | Abbreviated Journal | Acta Biomater |
| Volume | 16 | Issue | 16 | Pages | 215-222 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
Latest trends in dental restorative ceramics involve the development of full-contour 3Y-TZP ceramics which can avoid chipping of veneering porcelains. Among the challenges are the low translucency and the hydrothermal stability of 3Y-TZP ceramics. In this work, different trivalent oxides (Al2O3, Sc2O3, Nd2O3 and La2O3) were selected to dope 3Y-TZP ceramics. Results show that dopant segregation was a key factor to design hydrothermally stable and high-translucent 3Y-TZP ceramics and the cation dopant radius could be used as a controlling parameter. A large trivalent dopant, oversized as compared to Zr4+, exhibiting strong segregation at the ZrO2 grain boundary was preferred. The introduction of 0.2 mol% La2O3 in conventional 0.10.25 wt.% Al2O3-doped 3Y-TZP resulted in an excellent combination of high translucency and superior hydrothermal stability, while retaining excellent mechanical properties. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | S.l. | Editor | ||
| Language | Wos | 000351978600021 | Publication Date | 2015-02-04 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1742-7061; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.319 | Times cited | 54 | Open Access | |
| Notes | Fwo G043110n | Approved | Most recent IF: 6.319; 2015 IF: 6.025 | ||
| Call Number | c:irua:124421 | Serial | 1473 | ||
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| Author | Istomin, S.Y.; Morozov, A.V.; Abdullayev, M.M.; Batuk, M.; Hadermann, J.; Kazakov, S.M.; Sobolev, A.V.; Presniakov, I.A.; Antipov, E.V. | ||||
| Title | High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-\delta perovskites as prospective electrode materials for symmetrical SOFC | Type | A1 Journal article | ||
| Year | 2018 | Publication | Journal of solid state chemistry | Abbreviated Journal | J Solid State Chem |
| Volume | 258 | Issue | 258 | Pages | 1-10 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
La1-yCayFe0.5+x(Mg,Mo)(0.5-x)O3-delta oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mossbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-delta and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-delta) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-delta is oxygen deficient with delta approximate to 0.15. Oxides are stable in reducing atmosphere (Ar/H-2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1-xGdxO2-x/2 electrolyte mixtures treated at 1173-1373K, while Fe-rich compositions (x >= 0.1) react with Zr1-xYxO2-x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4-12.7 ppm K-1. In reducing atmosphere their TECs were found to increase up to 12.1-15.4 ppm K-1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H-2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000423650400001 | Publication Date | 2017-10-11 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-4596 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.299 | Times cited | 5 | Open Access | Not_Open_Access |
| Notes | ; This work was financially supported by Russian Science Foundation (project number 16-13-10327). ; | Approved | Most recent IF: 2.299 | ||
| Call Number | UA @ lucian @ c:irua:149283 | Serial | 4936 | ||
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| 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. | ||||
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| 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 | ||
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| 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. | ||||
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| 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 | ||
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| Author | Batuk, M.; Buffiere, M.; Zaghi, A.E.; Lenaers, N.; Verbist, C.; Khelifi, S.; Vleugels, J.; Meuris, M.; Hadermann, J. | ||||
| Title | Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se2 solar cells | Type | A1 Journal article | ||
| Year | 2015 | Publication | Thin solid films : an international journal on the science and technology of thin and thick films | Abbreviated Journal | Thin Solid Films |
| Volume | 583 | Issue | 583 | Pages | 142-150 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In,Ga)Se-2 (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aimof improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior to the selenization. We showed that the use of an Air/H2S burn-out step prior to the selenization step increases the CIGSe grain size and reduces the carbon content. However, it leads to the reduction of the solar cell efficiency from 4.5% in the reference sample down to 0.5% in the annealed sample. Detailed transmission electron microscopy analysis, including high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray mapping, was applied to characterize the microstructure of the film and to determine the relationship between microstructure and the solar cell performance. We demonstrated that the relatively low efficiency of the reference solar cells is related not only to the nanosize of the CIGSe grains and presence of the pores in the CIGSe layer, but also to the high amount of secondary phases, namely, In/Ga oxide (or hydroxide) amorphous matter, residuals of organicmatter (carbon), and copper sulfide that is formed at the CIGSe/MoSe2 interface. The annealing in H2S during the burn-out step leads to the formation of the copper sulfide at all grain boundaries and surfaces in the CIGSe layer, which results in the noticeably efficiency drop. (C) 2015 Elsevier B.V. All rights reserved. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Lausanne | Editor | ||
| Language | Wos | 000353812400024 | Publication Date | 2015-04-05 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0040-6090; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 1.879 | Times cited | 5 | Open Access | |
| Notes | Approved | Most recent IF: 1.879; 2015 IF: 1.759 | |||
| Call Number | c:irua:126009 | Serial | 845 | ||
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| Author | Batuk, M.; Vandemeulebroucke, D.; Ceretti, M.; Paulus, W.; Hadermann, J. | ||||
| Title | Topotactic redox cycling in SrFeO2.5+δ explored by 3D electron diffraction in different gas atmospheres | Type | A1 Journal article | ||
| Year | 2022 | Publication | Journal of materials chemistry A : materials for energy and sustainability | Abbreviated Journal | J Mater Chem A |
| Volume | Issue | Pages | |||
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
| Abstract |
For oxygen conducting materials applied in solid oxide fuel cells and chemical-looping processes, the understanding of the oxygen diffusion mechanism and the materials’ crystal structure at different stages of the redox reactions is a key parameter to control their performance. In this paper we report the first ever in situ 3D ED experiment in a gas environment and with it uncover the structure evolution of SrFeO2.5 as notably different from that reported from in situ X-ray and in situ neutron powder diffraction studies in gas environments. Using in situ 3D ED on submicron sized single crystals obtained from a high quality monodomain SrFeO2.5 single crystal , we observe the transformation under O2 flow of SrFeO2.5 with an intra- and interlayer ordering of the left and right twisted (FeO4) tetrahedral chains (space group Pcmb) into consecutively SrFeO2.75 with space group Cmmm (at 350°C, 33% O2) and SrFeO3-δ with space group Pm3 ̅m (at 400°C, 100% O2). Upon reduction in H2 flow, the crystals return to the brownmillerite structure with intralayer order, but without regaining the interlayer order of the pristine crystals. Therefore, redox cycling of SrFeO2.5 crystals in O2 and H2 introduces stacking faults into the structure, resulting in an I2/m(0βγ)0s symmetry with variable β. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000891928400001 | Publication Date | 0000-00-00 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2050-7488 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 11.9 | Times cited | Open Access | OpenAccess | |
| Notes | Financial support is acknowledged from the FWO-Hercules fund I003218N ‘Infrastructure for imaging nanoscale processes in gas/vapor or liquid environments’, from the University of Antwerp through grant BOF TOP 38689. This work was supported by the European Commission Horizon 2020 NanED grant number 956099. Financial support from the French National Research Agency (ANR) through the project “Structural induced Electronic Complexity controlled by low temperature Topotactic Reaction” (SECTOR No. ANR-14-CE36- 0006-01) is gratefully acknowledged. | Approved | Most recent IF: 11.9 | ||
| Call Number | EMAT @ emat @c:irua:192325 | Serial | 7229 | ||
| Permanent link to this record | |||||