Growth Induced Anisotropy in Sputtered GdCo Films

Abstract

Substrate bias effects on growth induced anisotropy in amorphous GdCo films have been investigated. Perpendicular anisotropy is induced with negative bias voltages higher than −30V. The induced anisotropy constant has close relations with Ar content and film density. With increasing bias voltages, both anisotropy constant and Ar content increase. Film density changes from 8.7 to 6.9 gm/cm3 for bias voltages of zero and −170V, respectively. The change in density may result from Ar inclusion and resultant void formation. An electric field distortion near the substrate surface gives a weak in‐plane anisotropy in addition to the perpendicular anisotropy. There is a critical thickness required to induce the perpendicular anisotropy at a given bias voltage. The critical thickness decreases with increasing bias voltages. The growth induced anisotropy of bias sputter deposited GdCo films could be explained by assuming shaped void formation.