title: Impact of Lanthanoid Substitution on the Structural and Physical Properties of an Infinite-Layer Iron Oxide.
abstract: The effect of lanthanoid (Ln = Nd, Sm, Ho) substitution on the structural and physical properties of the infinite-layer iron oxide SrFeO2was investigated by X-ray diffraction (XRD) at ambient and high pressure, neutron diffraction, and57Fe Mössbauer spectroscopy. Ln for Sr substituted samples up to ∼30% were synthesized by topochemical reduction using CaH2. While the introduction of the smaller Ln3+ion reduces the a axis as expected, we found an unusual expansion of the c axis as well as the volume. Rietveld refinements along with pair distribution function analysis revealed the incorporation of oxygen atoms between FeO2layers with a charge-compensated composition of (Sr1-xLnx)FeO2+x/2, which accounts for the failed electron doping to the FeO2layer. The incorporated partial apical oxygen or the pyramidal coordination induces incoherent buckling of the FeO2sheet, leading to a significant reduction of the Néel temperature. High-pressure XRD experiments for (Sr0.75Ho0.25)FeO2.125suggest a possible stabilization of an intermediate spin state in comparison with SrFeO2, revealing a certain contribution of the in-plane Fe-O distance to the pressure-induced transition.
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Takafumi
authors: T
authors: Yamamoto
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Hiroshi
authors: H
authors: Ohkubo
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.|The Hakubi Center for Advanced Research, Kyoto University , Yoshida-Ushinomiya-cho, Sakyo-ku, Kyoto 606-8302, Japan.
authors: Cédric
authors: C
authors: Tassel
authors: Micro/Nano Fabrication Hub, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University , Yoshida-Honmachi, Sakyo, Kyoto 606-8501, Japan.
authors: Naoaki
authors: N
authors: Hayashi
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Shota
authors: S
authors: Kawasaki
authors: Research Institute for Solid State Physics, University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors: Taku
authors: T
authors: Okada
authors: Research Institute for Solid State Physics, University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors: Takehiko
authors: T
authors: Yagi
authors: Australian Synchrotron Research Program, Australian Nuclear Science and Technology Organisation , PMB 1, Menai, New South Wales 2234, Australia.
authors: James
authors: J
authors: Hester
authors: Australian Synchrotron Research Program, Australian Nuclear Science and Technology Organisation , PMB 1, Menai, New South Wales 2234, Australia.
authors: Maxim
authors: M
authors: Avdeev
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Yoji
authors: Y
authors: Kobayashi
authors: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.|CREST, Japan Science and Technology Agency (JST) , Kawaguchi, Saitama 332-0012, Japan.
authors: Hiroshi
authors: H
authors: Kageyama