[14a-A501-1~13] 10.2 Fundamental and exploratory device technologies for spin

▲ [14a-A501-1] [Young Scientist Presentation Award Speech] Control of perpendicular magnetic anisotropy of Co thin films formed on a flexible substrate by using a biaxial stretching technique

〇Hiroki Matsumoto^1,2, Shinya Ota^1,2, Tomohiro Koyama^2,3, Daichi Chiba^2,3 (1.The Univ. of Tokyo, 2.ISIR, Osaka Univ., 3.CSRN-Osaka)

Keywords:inverse magnetostrictive effect, flexible substrate, perpendicular magnetic anisotropy

Magnetization direction of ferromagnetic metal thin films deposited on a flexible substrate can be controlled by uniaxially stretching the substrate. If a tensile strain is induced by stretching it along the x axis, compressive strain is induced both in the y and z axes owing to the Poisson’s effect. In an fcc(111)-oriented Co film, the stretch-induced shrinkage in the out-of-plane direction is expected to induce a perpendicular magnetic anisotropy (PMA). Although a PMA modulation by uniaxial stretching has been reported for Pt/Co/Pt tri-layer structure, the induced PMA is much smaller than the in-plane magnetic anisotropy induced along the stretched direction. To apply a much larger perpendicular compressive strain without inducing the in-plane anisotropy, we utilize a biaxial stretching technique. As a result, we successfully demonstrate the stretch-induced magnetization easy axis switching from in-plane to out-of-plane in Pt/Co/Pt.