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Takeda, Yukiharu; Pospil, J.*; Yamagami, Hiroshi; Yamamoto, Etsuji; Haga, Yoshinori
Physical Review B, 108(8), p.085129_1 - 085129_10, 2023/08
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Fujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Pospil, J.*; Yamamoto, Etsuji; Haga, Yoshinori
Physical Review B, 105(11), p.115128_1 - 115128_6, 2022/03
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)Pospil, J.*; Haga, Yoshinori; Miyake, Atsushi*; Kambe, Shinsaku; Tokunaga, Yo; Tokunaga, Masashi*; Yamamoto, Etsuji; Proschek, P.*; Voln, J.*; Sechovsk, V.*
Physical Review B, 102(2), p.024442_1 - 024442_13, 2020/07
Times Cited Count:6 Percentile:38.16(Materials Science, Multidisciplinary)Tateiwa, Naoyuki; Pospil, J.*; Haga, Yoshinori; Sakai, Hironori; Matsuda, Tatsuma*; Yamamoto, Etsuji
Progress in Nuclear Science and Technology (Internet), 5, p.104 - 107, 2018/11
Uranium ferromagnetic superconductors UGe, URhGe and UCoGe have attracted much attention from both theoretical and experimental sides since the same 5 electrons underlie carry both the ferromagnetism and superconductivity. Recently, we have analysed 69 uranium, 7 neptunium, and 4 plutonium ferromagnets with spin fluctuation theory originally developed for researches on itinerant ferromagnets in the 3 transition metals and their intermetallics. The applicability of the spin fluctuation theory to the actinide 5 system has been confirmed and the itinerant character of the 5f electrons is suggested in the actinide ferromagnets. In this conference, two results will be shown. One is the results of the analyses on 80 actinide ferromagnets and the other is the pressure dependence of the spin fluctuation parameters in UGe.
Pospil, J.*; Haga, Yoshinori; Kohama, Yoshimitsu*; Miyake, Atsushi*; Kambe, Shinsaku; Tateiwa, Naoyuki; Valika, M.*; Proschek, P.*; Prokleka, J.*; Sechovsk, V.*; et al.
Physical Review B, 98(1), p.014430_1 - 014430_7, 2018/07
Times Cited Count:16 Percentile:61.26(Materials Science, Multidisciplinary)Tateiwa, Naoyuki; Pospil, J.*; Haga, Yoshinori; Yamamoto, Etsuji
Physical Review B, 97(6), p.064423_1 - 064423_10, 2018/02
Times Cited Count:13 Percentile:48.71(Materials Science, Multidisciplinary)The critical behavior of dc magnetization in the uranium ferromagnet URhAl with the hexagonal ZrNiAl-type crystal structure has been studied around the ferromagnetic transition temperature . The critical exponent for the temperature dependence of the spontaneous magnetization below , for the magnetic susceptibility, and for the magnetic isotherm at have been obtained. We have determined the critical exponents as = 0.287 0.005, = 1.47 0.02, and = 6.08 0.04 by the scaling analysis and the critical isotherm analysis. These critical exponents satisfy the Widom scaling law . The determined exponents can be explained with the results of the renormalization group approach for a two-dimensional Ising system coupled with long-range interactions.
Tateiwa, Naoyuki; Pospil, J.*; Haga, Yoshinori; Sakai, Hironori; Matsuda, Tatsuma*; Yamamoto, Etsuji
Physical Review B, 96(3), p.035125_1 - 035125_15, 2017/07
Times Cited Count:25 Percentile:72.37(Materials Science, Multidisciplinary)We have carried out an analysis of magnetic data in 69 uranium, 7 neptunium and 4 plutonium ferromagnets with the spin fluctuation theory developed by Takahashi (Y. Takahashi, J. Phys. Soc. Jpn. , 3553 (1986)). The basic and spin fluctuation parameters of the actinide ferromagnets are determined and the applicability of the spin fluctuation theory to actinide system has been discussed. Itinerant ferromagnets of the transition metals and their intermetallics follow a generalized Rhodes-Wohlfarth relation . Here, , , , and are the spontaneous and effective magnetic moments, the Curie temperature and the width of spin fluctuation spectrum in energy space, respectively. The same relation is satisfied for in the most of the actinide ferromagnets.
Tateiwa, Naoyuki; Pospil, J.*; Haga, Yoshinori; Sakai, Hironori; Yamamoto, Etsuji; Matsuda, Tatsuma*
no journal, ,
We have carried out an analysis of magnetic data in 69 uranium, 7 neptunium and 4 plutonium ferromagnets with the spin fluctuation theory developed by Takahashi (Y. Takahashi, J. Phys. Soc. Jpn. , 3553 (1986)). Itinerant ferromagnets of the transition metals and their intermetallics follow a generalized Rhodes-Wohlfarth relation between and viz., . Here, , , and are the spontaneous and effective magnetic moments, the Curie temperature and the width of spin fluctuation spectrum in energy space, respectively. The same relation is satisfied for in the actinide ferromagnets.
Tateiwa, Naoyuki; Haga, Yoshinori; Yamamoto, Etsuji; Pospil, J.*
no journal, ,
We have studied uranium ferromagnetic superconductivity of the actinide electrons system. The applicability of the spin fluctuation theory to the actinide system were investigated. In the previous JPS meeting, we reported the result of the magnetization measurement on uranium ferromagnetic superconductors UGe. In this talk, we present the generalized Rhode-Wohlfarth relation in UGe and spin fluctuation parameters in URhGe-UCoGe system.