[20p-131-1~8] 【CS.9】 10.1 新物質・新機能創成（作製・評価技術）, 10.2 スピン基盤技術・萌芽的デバイス技術, 10.3 スピンデバイス・磁気メモリ・ストレージ技術, 10.4 半導体スピントロニクス・超伝導・強相関のコードシェアセッション

▲ [20p-131-8] Effect of lattice distortion on voltage-controlled magnetic anisotropy at MgO/CoFe interface

〇Masahito Tsujikawa^1,2、Masafumi Shirai^1,2,3 (1.RIEC, Tohoku Univ.、2.CSRN, Tohoku Univ.、3.WLRCS, Tohoku Univ.)

キーワード：Spintronics, Voltage-controlled magnetic anisotropy, first principles calculation

Recently, the enhancement of voltage-controlled magnetic anisotropy (VCMA) effect by the lattice distortion is reported. We investigated the origin of the enhancement of VCMA by the lattice distrotion by using first principles calculation. We estimated electric-field moduclation of magnetic anisotropy energy (MAE) for the Al(6ML)/CoFe(8ML)/MgO(5ML) film as a function of in-plane lattice constant a. The VCMA of Al/CoFe/MgO film without distortion (a = 2.83À) is estimated to be 8.0 fJ/Vm. By introducing 2.1% in-plane compressive strain (a = 2.77 À), the VCMA is enhanced to be 14.4 fJ/Vm. From the analysis of the band filling effect on the MAE, we found that the MAE of the interfacial Fe layer becomes sensitive to the valence electron numbers at the lattice constant a near 2.77 À. By introducing in-plane compressive strain, occupied d_x²_-y² and unoccupied d_xy orbital components of the bands close to the Fermi energy contributed to perpendicular magnetic anisotropy, and thus the MAE becomes sensitive to the valence electron numbers.