Magnetic recording medium, method for manufacturing recording medium and magnetic recordation apparatus

Abstract

A grain diameter controlling crystalline layer comprising crystalline grains of a metal selected from the group consisting essentially of Cu, Ni, Rh and Pt was formed on a substrate. Then, deposited atom layer of at least one element selected from the group consisting of oxygen and carbon was formed on the surface of the grain diameter control layer. A magnetic recording layer was deposited on the atoms deposited grain diameter controlling crystalline layer. Then a magnetic recording medium in which the magnetic crystalline grains has small grain diameter and small grain diameter distribution, and the magnetic recording medium shows increased signal to noise ratio at high recording density.

1 . A method for producing magnetic recording medium, comprising:
 a process for forming a grain diameter control under-layer comprising crystalline grains of at least one selected from the group consisting essentially of Cu, Ni, Rh and Pt on a substrate;   a process for forming an deposited atom layer of at least one element selected from the group consisting of oxygen and carbon atoms on the grain diameter control layer surface; and   a process for forming a magnetic recording layer on the deposited atom layer formed grain diameter control under-layer on the substrate.   
     
     
         2 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the deposited atom layer at least one element selected from the group consisting of oxygen and carbon atoms in an average areal density range from 1×10 13  atoms/cm 2  to 1×10 15  atoms/cm 2  is formed at the process for forming an deposited atom layer.   
     
     
         3 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the grain diameter control under-layer comprising 50 nm or larger than 50 nm crystalline grains of at least one selected from the group consisting essentially of Cu, Ni, Rh and Pt is formed at the process for forming a grain diameter control under-layer, and the element deposited atom layer at least one element selected from the group consisting of oxygen and carbon is formed on the grain diameter control under-layer surface at the process for forming an deposited atom layer.   
     
     
         4 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the grain diameter control layer comprising the crystalline grains of at least one selected from the group consisting essentially of Cu, Ni, and Rh oriented their (100) planes parallel to the substrate surface is formed at the process for forming a grain diameter control layer.   
     
     
         5 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the magnetic crystalline grains are arranged essentially in a form of tetragonal lattice structure in the magnetic recording-layer plane at the process of forming a magnetic recording-layer.   
     
     
         6 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the grain diameter control layer comprising the crystalline grains of Pt oriented their (111) planes parallel to the substrate surface is formed at the process for forming a grain diameter control layer.   
     
     
         7 . The method for producing magnetic recording medium as set forth in  claim 6 ,
 wherein the magnetic crystalline grains are arranged essentially in a form of hexagonal lattice structure in the magnetic recording-layer plane at the process of forming a magnetic recording-layer.   
     
     
         8 . The method for producing magnetic recording medium as set forth in  claim 1 ,
 wherein the magnetic crystalline grains in the magnetic recording-layer are formed in an average areal density range from 1×10 12  grains/cm 2  to 8×10 12  grains/cm 2  at the process for forming a magnetic recording-layer.