Effects of substrate bias with recording layer on perpendicular magnetic media

A direct current (DC) bias is added on the substrate during the deposition of the recording layer of perpendicular magnetic recording media. It has been found that the bias has significant effects on the magnetic properties, such as coercivity, nucleation field, squareness, and domain size, and microstructure, such grain size, grain size segregation, and c-axis orientation. It is also observed that the roughness of the surface is reduced by using the bias. The mechanism of the bias effect is discussed.