Magnetic anisotropy in nickel and cobalt films obliquely deposited by sputtering

Abstract

The in-plane magnetic anisotropy was investigated in nickel and cobalt films obliquely deposited by rf diode sputtering. The incidence angle was 45° and the substrate temperature Ts ranged from 305 to 623 K. At a pressure of 10 Pa, a uniaxial anisotropy with the easy axis parallel to the incidence plane is induced in nickel films. The magnitude of the anisotropy decreases with increasing Ts. Its origin is the anisotropic stress, since optical and electrical measurements and the X-ray analysis showed negligible contributions of the shape anisotropy of crystallites and the preferred orientation. In cobalt films, on the contrary, the magnetic anisotropy is extremely small irrespective of Ts. However, by increasing the pressure (20–26 Pa) we could obtain a large anisotropy with the easy axis perpendicular to the incidence plane at the low Ts range (Ts≤ 360 K). The {0002} pole figure revealed that this anisotropy originates from the c-axis alignment.