Bias Effect on Compositional Separation in Sputtered Co–Cr Films

Abstract

The effect of dc substrate bias on compositional separation (CS) in sputtered Co–Cr films is examined using spin-echo 59 Co NMR and transmission electron microscopy. It is observed that the degree of CS decreases monotonically with increasing negative bias voltage. Slight positive bias voltage, however, is found to enhance CS, resulting in increased saturation magnetization and a higher anisotropy field. The elimination of Ar ion bombardment at the film surface during deposition is thought to be effective in enhancing CS.