Behavior of perpendicular recording materials in Cl and S containing atmospheres

The corrosion behavior of Co-Cr and Ni-Fe alloys is reported after exposure to Cl2, SO2, and O2containing test atmospheres at various relative (RH) humidities. Surface Chemistry, physical features, and magnetic properties were characterized. The Ni-Fe alloys exhibited excellent corrosion resistance in elevated RH atmospheres. Co-Cr alloys showed little change in magnetic properties even when significant chemical penetration of the film occurred. Substrate chemical composition proved to be an important factor in sputtered film corrosion behavior.