Corrosion resistance of low coercivity, high moment FeXN (X=Rh, Mo) thin film head materials

Electrochemical corrosion of low coercivity, high moment FeXN (X=Rh, Mo) films were tested in 0.5 M NaCl electrolyte. The testing conditions emulate the extreme environment to which thin film heads are exposed during packaging, storage and subsequent application. The addition of Rh or Mo to FeN films improves the corrosion resistance significantly. In 0.5 M NaCl electrolyte and with the protection of the native oxide layer, the corrosion resistance of FeRhN films is as good as Permalloy. More importantly, FeRhN films show better overall pitting resistance than Permalloy.