Enhanced orbital magnetic moment in FeCo nanogranules observed by Barnett effect

バーネット効果によるFeCoナノ粒子における軌道磁気モーメント増大の観測

緒方 裕大; 中堂 博之 ; Gu, B.; 小林 伸聖*; 小野 正雄  ; 針井 一哉; 松尾 衛; 齊藤 英治; 前川 禎通

Ogata, Yudai; Chudo, Hiroyuki; Gu, B.; Kobayashi, Nobukiyo*; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Saito, Eiji; Maekawa, Sadamichi

The gyroscopic g factor, , of FeCo nanogranules embedded in a matrix of MgF (FeCo-MgF) was determined by measuring the magnetic-field generation from a rotating sample due to the Barnett effect. The value of the FeCo-MgF is estimated to be 1.76 0.11. The orbital contribution to the magnetic moment in the FeCo nanogranules was found to be quite large compared with that in bulk FeCo, being consistent with a density-functional-theory calculation that shows that the orbital magnetic moment may increase at the FeCo/MgF interfaces. The result suggests that the orbital magnetic moment is enhanced by symmetry breaking at the surface of the FeCo nanogranules.