Browsing by Author "Ishigaki, T"

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    New perovskite-related structure family of oxide-ion conducting materials NdBaInO4
    (ACS Publications, 2014-03-21) Fujii, K; Esaki, Y; Omoto, K; Yashima, M; Hoshikawa, A; Ishigaki, T; Hester, JR
    Oxide-ion conducting ceramic materials, which include pure oxide-ion conductors and mixed oxide-ion and electronic or hole conductors, have received considerable attention because of their potential application for oxygen separation membranes, oxygen sensors, and solid oxide fuel cells (SOFCs) electrolytes and cathodes.1 Perovskite-type and perovskite-related materials have been widely investigated as oxide-ion conductors.2 For example, the K2NiF4-type compounds are known to exhibit high oxide-ion conductivity.3 Because the oxide-ion conductivity is strongly dependent on crystal structure, it is necessary to design and synthesize novel materials belonging to a new structure family for further innovative developments of the oxide-ion conductors. Herein, we report a new perovskite-related structure family with AA′BO4 composition, which exhibits oxide-ion conduction. Here, A and A′ are relatively larger cations and B is a smaller cation. In this work we have succeeded in solving the crystal structure of NdBaInO4 and show oxide-ion conduction in NdBaInO4. © 2014, American Chemical Society.
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    Quantified zero thermal expansion in magnetic R2Fe17-based intermetallic compounds (R = rare earth)
    (American Chemical Society, 2023-06-13) Cao, YL; Matsukawa, T; Gibbs, A; Avdeev, M; Wang, CW; Wu, H; Huang, QZ; Ohoyama, K; Ishigaki, T; Zhou, H; Li, Q; Miao, J; Lin, K; Xing, XR
    Zero thermal expansion (ZTE) has been a fascinating task for the past few decades due to its great scientific and practical merits. To realize ZTE, negative thermal expansion is typically employed by chemical substitutions on tuning structure features, which often relies on trial and error. Here, we report on exploring quantification of thermal expansion with magnetic ordering in an intermetallic class of R2Fe17 (R = rare earth), which can accurately determine the ZTE composition using a documented database. It demonstrates that the magnetic ordering of the Fe-sublattice contributes to the thermal expansion anomaly through simultaneous examinations of magnetization and neutron powder diffraction. Alternative elements can be manipulated on a Fe-sublattice to control both the total ordered magnetic moments of the Fe-sublattice and Curie temperature, which tailors the temperature variation of the magnetic contributions on thermal expansion. The current work might point to a future for ZTE high throughput searches, anticipated to benefit applications. © 2023 American Chemical Society