Magnetic disk and method for manufacturing same

Abstract

Provided is a method of manufacturing a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer ( 20 ) which is formed on a disk substrate 10 directly or via an intermediate layer and which has non-magnetic regions between granular columnar particles; and an auxiliary recording layer ( 22 ) which is formed on the granular magnetic recording layer 20 and which causes exchange interaction among the granular columnar particles, wherein the auxiliary recording layer ( 22 ) contains 0.1 to 3 moles of oxygen.

1 . A method for manufacturing a magnetic disk comprising: a magnetic recording layer formation step of forming at least a granular magnetic recording layer on a disk substrate; and an auxiliary recording layer formation step of forming an auxiliary recording layer on the magnetic recording layer, wherein the auxiliary recording layer containing 0.1 to 3 mol % oxygen is formed in the auxiliary recording layer formation step. 
     
     
         2 . The method for manufacturing a magnetic disk according to  claim 1 , wherein the auxiliary recording layer is formed by sputtering with use of a sputtering target containing oxide in the auxiliary recording layer formation step. 
     
     
         3 . The method for manufacturing a magnetic disk according to  claim 1 , wherein the auxiliary recording layer is formed by reactive sputtering where oxygen is incorporated at a partial pressure of 0.5 to 3% in the auxiliary recording layer formation step. 
     
     
         4 . The method for manufacturing a magnetic disk according to  claim 1 , wherein a non-magnetic separation layer is interposed between the granular magnetic recording layer and the auxiliary recording layer. 
     
     
         5 . The method for manufacturing a magnetic disk according to  claim 4 , wherein the granular magnetic recording layer is formed of two or more layers.