傾斜配向磁性膜の本質的な一軸異方性の定量解析

抄録

  The tilt angle of the crystal orientation axis was quantitatively evaluated for tilt-oriented magnetic film, and a method for separating the effective crystal magnetic anisotropy energy K_u^eff of the film from the intrinsic crystal magnetic anisotropy energy K_u^grain of magnetic crystal particles was investigated. As a measurement sample, a Co/Pt multilayer magnetic film was formed on an underlayer composed of Ta and Pt by sputtering with a cylindrical collimator at an inclined incident angle of 60 deg. To quantitatively evaluate the crystal inclination angle, a rocking curve was measured with a three-dimensional polar-coordinate X-ray diffraction system, and in addition, the angle dependence of the magnetic switching field H_sw was measured with a Polar-Kerr system. It was also shown that both K_u^eff and K_u^grain can be separated quantitatively even in tilt-oriented magnetic films by correcting the inclination angle of the crystal orientation axis when deriving the crystal magnetic anisotropy energy from a torque curve. The larger the angle of the crystal orientation axis, the larger the difference from the case without correction. Therefore, the derived equation becomes more effective as the inclination angle of the crystal axis gets larger.