Effects of Substrate Bias With Recording Layer on the Magnetic Properties and Microstructure of Perpendicular Magnetic Recording Media

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