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ヤマガミ ヒロシ
YAMAGAMI HIROSHI
山上 浩志 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2015/08/15 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Gradual Localization of 5f States in Orthorhombic UTX Ferromagnets: Polarized Neutron Diffraction Study of Ru Substituted UCoGe |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN |
| 出版社・発行元 | PHYSICAL SOC JAPAN |
| 巻・号・頁 | 84(8),pp.084707-084707 |
| 著者・共著者 | Michal Valiska,Jiri Pospisil,Anne Stunault,Yukiharu Takeda,Beatrice Gillon,Yoshinori Haga,Karel Prokes,Mohsen M. Abd-Elmeguid,Gwilherm Nenert,Tetsuo Okane,Hiroshi Yamagami,Laurent Chapon,Arsene Gukasov,Alain Cousson,Etsuji Yamamoto,Vladimir Sechovsky |
| 概要 | We report on a microscopic study of the evolution of ferromagnetism in the Ru substituted ferromagnetic superconductor (FM SC) UCoGe crystallizing in the orthorhombic TiNiSi-type structure. For that purpose, two single crystals with composition UCo0.97Ru0.03Ge and UCo0.88Ru0.12Ge have been prepared and characterized by magnetization, AC susceptibility, specific heat and electrical resistivity measurements. Both compounds have been found to order ferromagnetically below T-C = 6.5 and 7.5 K, respectively, which is considerably higher than the T-C = 3 K of the parent compound UCoGe. The higher values of T-C are accompanied by enhanced values of the spontaneous moment mu(spont) = 0.11 mu(B)/f.u. and mu(spont) = 0.21 mu(B)/f.u., respectively in comparison to the tiny spontaneous moment of UCoGe (about 0.07 mu(B)/f.u.). No sign of superconductivity was detected in either compound. The magnetic moments of the samples were investigated on the microscopic scale using polarized neutron diffraction (PND) and for UCo0.88Ru0.12Ge also by soft X-ray magnetic circular dichroism (XMCD). The analysis of the PND results indicates that the observed enhancement of ferromagnetism is mainly due to the growth of the orbital part of the uranium 5 f moment mu(U)(L), reflecting a gradual localization of the 5 f electrons with Ru substitution. In addition, the parallel orientation of the U and Co moments has been established in both substituted compounds. The results are discussed and compared with related isostructural ferromagnetic UTX compounds (T: transition metals, X: Si, Ge) in the context of a varying degree of the 5 f-ligand hybridization. |
| DOI | 10.7566/JPSJ.84.084707 |
| ISSN | 0031-9015/1347-4073 |
| PermalinkURL | http://journals.jps.jp/doi/pdf/10.7566/JPSJ.84.084707 |