Amorphous Gd-Fe alloy films prepared by RF cosputtering technique

Amorphous GdxFe1-x(0 < x < 0.35) thin films were prepared by RF cosputtering using an iron target covered partially with small gadolinium pieces. The composition dependences of saturation magnetization, hysteresis curves, and domain structures were studied. Spark-like domains were observed when the magnetization was reversed from saturation. The uniaxial anisotropy was induced perpendicular to the film plane. The average value of the perpendicular uniaxial anisotropy constant Ku was about 2 × 10⁵erg/cm³. Ku, however, decreases as the saturation moment decreases in the vicinity of room temperature compensation. The stripe domain width was varied from 0.3 to 4 microns as the saturation moment decreased from 300 to 20 gauss. These magnetic properties of amorphous Gd-Fe sputtered films are similar to those of amorphous Gd-Co films.