Magnetic anisotropy of soft-underlayer induced by magnetron field

Abstract

A perpendicular magnetic recording medium having a substrate and a magnetic underlayer on the substrate, the magnetic underlayer having an easy axis of magnetization substantially directed in a radial or transverse direction, and a process for manufacturing the perpendicular magnetic recording medium are disclosed.

1 - 21 . (canceled)  
     
     
         22 . A method for manufacturing a magnetic recording disk for perpendicular recording, comprising: 
 applying a magnetron field and    depositing an underlayer on a substrate,    wherein the underlayer comprises an easy axis of magnetization directed in a radial direction of the magnetic recording disk.    
     
     
         23 . The method of  claim 22 , further comprising heating the substrate.  
     
     
         24 . The method of  claim 22 , wherein the depositing an underlayer is by sputtering.  
     
     
         25 . The method of  claim 24 , wherein the sputtering is a reactive sputtering.  
     
     
         26 . The method of  claim 22 , wherein the substrate is kept stationary during said depositing a magnetic underlayer.  
     
     
         27 . The method of  claim 26 , wherein a diameter of a magnetron source producing the magnetron field is larger than a diameter of the substrate.  
     
     
         28 . The method of  claim 22 , wherein the substrate is rotated during said depositing a magnetic underlayer.  
     
     
         29 . The method of  claim 28 , wherein a size of a magnetron source producing the magnetron field is smaller or comparable to a diameter of the substrate.  
     
     
         30 . The method of  claim 29 , wherein the substrate is placed off-center with respect to the magnetron source.