Perpendicular magnetic recording medium

Abstract

A perpendicular magnetic recording medium has a substrate, a soft magnetic underlayer formed on the substrate, arrayed soft magnetic dots formed on the soft magnetic underlayer, and a ferromagnetic recording layer formed on the soft magnetic dots and having magnetic anisotropy in a direction perpendicular to a surface of the substrate.

1 . A perpendicular magnetic recording medium, comprising: 
 a substrate;    a flat soft magnet underlayer formed on the substrate;    arrayed soft magnetic dots formed on the flat soft magnetic underlayer; and    a nonmagnetic layer formed on the flat soft magnetic underlayer and the soft magnetic dots;    a ferromagnetic recording layer formed on the non-magnetic layer and having magnetic anisotropy in a direction perpendicular to a surface of the substrate.    
     
     
         2 . The perpendicular magnetic recording medium according to  claim 1 , further comprising a nonmagnetic layer between the soft magnetic dots and the ferromagnetic recording layer.  
     
     
         3 . The perpendicular magnetic recording medium according to  claim 2 , wherein the nonmagnetic layer is embedded between the adjacent soft magnetic dots, a surface of the nonmagnetic layer being substantially flat.  
     
     
         4 . The perpendicular magnetic recording medium according to  claim 1 , wherein the soft magnetic underlayer and the soft magnetic dots are in contact with each other.  
     
     
         5 . The perpendicular magnetic recording medium according to  claim 1 , further comprising a nonmagnetic layer having a thickness of 10 nm or less between the soft magnetic underlayer and the soft magnetic dots.  
     
     
         6 . The perpendicular magnetic recording medium according to  claim 1 , wherein a thickness of the soft magnetic dots is 100 nm or less.  
     
     
         7 - 17 . (canceled)  
     
     
         18 . The perpendicular magnetic recording medium according to  claim 1 , wherein the flat soft magnetic underlayer and the arrayed soft magnetic dots are formed of different materials.  
     
     
         19 . The perpendicular magnetic recording medium according to  claim 1 , wherein the flat soft magnetic underlayer and the arrayed soft magnetic dots are formed of a same material.