Magnetostriction and Perpendicular Magnetic Anisotropy of Amorphous GdFeCo Thin Films

The saturation magnetostriction constant λs, and the perpendicular magnetic anisotropy K u of amorphous Gd x (Fe100-y Co y )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 V b, although K u strongly depended on V b.