Browsing by Author "Fukazawa, H"

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    Block magnetism coupled with local distortion in the iron-based spin-ladder compound BaFe 2 Se 3
    (American Physical Society, 2012-02-22) Nambu, Y; Ohgushi, K; Suzuki, S; Du, F; Avdeev, M; Uwatoko, Y; Munakata, K; Fukazawa, H; Chi, S; Ueda, Y; Sato, TJ
    Magnetism in the insulating BaFe2Se3 was examined through susceptibility, specific heat, resistivity, and neutron diffraction measurements. After formation of a short-range magnetic correlation, a long-range ordering was observed below TN∼255 K. The transition is obscured by bulk properties. Magnetic moments (∥a) are arranged to form a Fe4 ferromagnetic unit, and each Fe4 stacks antiferromagnetically. This block magnetism is of the third type among magnetic structures of ferrous materials. The magnetic ordering drives unusually large distortion via magnetoelastic coupling. ©2012 American Physical Society
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    Temperature and composition phase diagram in the iron-based ladder compounds Ba1−xCsxFe2Se3
    (American Physical Society, 2015-05-28) Hawai, T; Nambu, Y; Ohgushi, K; Du, F; Hirata, Y; Avdeev, M; Uwatoko, Y; Sekine, Y; Fukazawa, H; Ma, J; Chi, S; Ueda, Y; Yoshizawa, H; Sato, TJ
    We investigated the iron-based ladder compounds (Ba,Cs)Fe2Se3. Their parent compounds BaFe2Se3 and CsFe2Se3 have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe2Se3 is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe2Se3 is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe2Se3, but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures. ©2015 American Physical Society