Magnetostriction and Perpendicular Magnetic Anisotropy of Amorphous GdFeCo Thin Films

The saturation magnetostriction constant λs, and the perpendicular magnetic anisotropy Ku of amorphous Gdx(Fe100-yCoy)100-x(9.5<x<50) films prepared by dc-biased rf sputtering have been measured at room temperature. In films with high Co concentration, λs showed strong dependence on Gd content, whereas in Fe-rich films, λs showed weak dependence. Furthermore, it was confirmed that λs was not affected by the substrate bias voltage Vb, although Ku strongly depended on Vb.