Perpendicular Magnetic Anisotropy in Gd-Co Films Prepared by Ion-Beam Sputtering

The increase in perpendicular magnetic anisotropy in RF sputtered Gd-Co films with application of a negative bias voltage is thought to originate in structural changes due to resputtering effects. Dual-ion-beam sputtering was used to form Gd-Co films, and the relation between perpendicular magnetic anisotropy and resputtering was studied. In experiments using both dual-ion-beam sputtering and a single ion gun, Ku decreased monotonically with increasing Gd concentration. Hence increases in perpendicular anisotropy can be explained directly by decreases in Gd concentration together with the Gd content dependence of the perpendicular anisotropy.