FeCoSiの磁化過程が与える長距離磁気秩序と磁区との相関

Correlation between the long-range magnetic order and the magnetic domain structure in FeCoSi during the magnetization process

武田 全康  ; 遠藤 康夫; 小野瀬 佳文*; 加倉井 和久; 鈴木 淳市; 十倉 好紀*

Takeda, Masayasu; Endo, Yasuo; Onose, Yoshinori*; Kakurai, Kazuhisa; Suzuki, Junichi; Tokura, Yoshinori*

強磁性金属FeCoSi()は、反対称相互作用による長距離らせん磁気秩序を示すが、対称性の低い(B20型)立方晶故にカイラル特性を示す。偏極中性子小角散乱による詳細な磁化過程の測定により磁区構造がもたらす磁気長距離秩序構造の詳細から磁気液晶相の相転移を明らかにした。

A ferromagnetic metal, FeCoSi (), has a long-period helical spin structure due to the Dzyalosinsky-Moriya interaction. The Chirality of the helical structure decides either clockwise or anti-clockwise because the cubic B20 structure lacks the inversion center. We conclude that a new magnetic phase (a magnetic liquid crystal phase) exists in FeCoSi under the external magnetic fields judging from the detailed magnetization process determined by polarized neutron small angle scattering measurements.