| Records |
| Author |
Tunca, B.; Lapauw, T.; Delville, R.; Neuville, D.R.; Hennet, L.; Thiaudiere, D.; Ouisse, T.; Hadermann, J.; Vleugels, J.; Lambrinou, K. |
| Title |
Synthesis and Characterization of Double Solid Solution (Zr,Ti)(2)(Al,Sn)C MAX Phase Ceramics |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| Volume |
58 |
Issue |
10 |
Pages |
6669-6683 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Quasi phase-pure (>98 wt %) MAX phase solid solution ceramics with the (ZryTi)(2)(Al-0.5,Sn-0.5)C stoichiometry and variable Zr/Ti ratios were synthesized by both reactive hot pressing and pressureless sintering of ZrH2, TiH2, Al, Sn, and C powder mixtures. The influence of the different processing parameters, such as applied pressure and sintering atmosphere, on phase purity and microstructure of the produced ceramics was investigated. The addition of Sn to the (Zr,Ti)(2)AlC system was the key to achieve phase purity. Its effect on the crystal structure of a 211-type MAX phase was assessed by calculating the distortions of the octahedral M6C and trigonal M(6)A prisms due to steric effects. The M(6)A prismatic distortion values were found to be smaller in Sn-containing double solid solutions than in the (Zr,Ti)(2)AlC MAX phases. The coefficients of thermal expansion along the < a > and < c > directions were measured by means of Rietveld refinement of high-temperature synchrotron X-ray diffraction data of (Zr1-x,Ti-x)(2)(Al-0.5,Sn-0.5)C MAX phase solid solutions with x = 0, 0.3, 0.7, and 1. The thermal expansion coefficient data of the Ti-2(Al-0.5,Sn-0.5)C solid solution were compared with those of the Ti2AlC and Ti2SnC ternary compounds. The thermal expansion anisotropy increased in the (Zr,Ti)(2)(Al-0.5,Sn-0.5)C double solid solution MAX phases as compared to the Zr-2(Al-0.5,Sn-0.5)C and Ti-2(Al-0.5,Sn-0.5)C end-members. |
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Place of Publication |
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Wos |
000469304700014 |
Publication Date |
2019-05-01 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor  |
4.857 |
Times cited |
3 |
Open Access |
Not_Open_Access |
| Notes |
; H. Roussel and D. Pinek are acknowledged for the Ti<INF>2</INF>SnC single-crystal production and high-temperature XRD measurements performed at Grenoble INP-LMGP-CMTC. This research was funded partly by the European Atomic Energy Community's (Euratom) Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 604862 (FP7MatISSE), and partly by the Euratom research and training programme 2014-2018 under Grant Agreement No. 740415 (H2020 IL TROVATORE). T.L. thanks the Agency for Innovation by Science and Technology (IWT), Flanders, Belgium, for Ph.D. Grant No. 131081. B.T. acknowledges the financial support of the SCK.CEN Academy for Nuclear Science and Technology. All authors gratefully acknowledge Synchrotron SOLEIL for the allocated time at the DIFFABS beamline in association with Project 20161410 entitled “Investigation of (Zr-Ti)-Al-C MAX phases with in-situ high-temperature XRD” and the Hercules Foundation for Project AKUL/1319 (CombiS(T)EM). ; |
Approved |
Most recent IF: 4.857 |
| Call Number |
UA @ admin @ c:irua:160318 |
Serial |
5261 |
| Permanent link to this record |
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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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Place of Publication |
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Editor |
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Wos |
000494894400062 |
Publication Date |
2019-11-04 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.857 |
Times cited |
1 |
Open Access |
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| Notes |
We thank P. Manuel for assistance collecting the neutron powder diffraction data. We thank The Leverhulme Trust grant award RPG-2014-366 “Topochemical reduction of 4d and 5d transition metal oxides” for supporting this work. Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Investigation by TEM was supported through the FWO grant G035619N. |
Approved |
Most recent IF: 4.857 |
| Call Number |
EMAT @ emat @c:irua:164625 |
Serial |
5434 |
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| Author |
Leinders, G.; Baldinozzi, G.; Ritter, C.; Saniz, R.; Arts, I.; Lamoen, D.; Verwerft, M. |
| Title |
Charge Localization and Magnetic Correlations in the Refined Structure of U3O7 |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
| Volume |
60 |
Issue |
14 |
Pages |
10550-10564 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Atomic arrangements in the mixed-valence oxide U3O7 are refined from high-resolution neutron scattering data. The crystallographic model describes a long-range structural order in a U60O140 primitive cell (space group P42/n) containing distorted cuboctahedral oxygen clusters. By combining experimental data and electronic structure calculations accounting for spin–orbit interactions, we provide robust evidence of an interplay between charge localization and the magnetic moments carried by the uranium atoms. The calculations predict U3O7 to be a semiconducting solid with a band gap of close to 0.32 eV, and a more pronounced charge-transfer insulator behavior as compared to the well-known Mott insulator UO2. Most uranium ions (56 out of 60) occur in 9-fold and 10-fold coordinated environments, surrounding the oxygen clusters, and have a tetravalent (24 out of 60) or pentavalent (32 out of 60) state. The remaining uranium ions (4 out of 60) are not contiguous to the oxygen cuboctahedra and have a very compact, 8-fold coordinated environment with two short (2 × 1.93(3) Å) “oxo-type” bonds. The higher Hirshfeld charge and the diamagnetic character point to a hexavalent state for these four uranium ions. Hence, the valence state distribution corresponds to 24/60 × U(IV) + 32/60 U(V) + 4/60 U(VI). The tetravalent and pentavalent uranium ions are predicted to carry noncollinear magnetic moments (with amplitudes of 1.6 and 0.8 μB, respectively), resulting in canted ferromagnetic order in characteristic layers within the overall fluorite-related structure. |
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Place of Publication |
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Wos |
000675430900049 |
Publication Date |
2021-07-19 |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.857 |
Times cited |
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Open Access |
OpenAccess |
| Notes |
Financial support for this research was partly provided by the Energy Transition Fund of the Belgian FPS Economy (Project SF-CORMOD – Spent Fuel CORrosion MODeling). This work was performed in part using HPC resources from GENCI-IDRIS (Grants 2020-101450 and 2020-101601), and in part 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. GL thanks E. Suard and C. Schreinemachers for assistance during the neutron scattering experiments at the ILL. GB acknowledges V. Petříček for suggestions on using JANA2006. |
Approved |
Most recent IF: 4.857 |
| Call Number |
EMAT @ emat @c:irua:179907 |
Serial |
6801 |
| Permanent link to this record |
