Magnetic recording medium and magnetic storage apparatus

Abstract

A magnetic recording medium includes a substrate, multiple underlayers formed on the substrate, and a magnetic layer foisted on the multiple underlayers. A main component of the magnetic layer is an alloy having a L1 0 structure. At least one of the multiple underlayers is a crystalline underlayer containing W. The W is a main component of the crystalline underlayer. The crystalline underlayer further contains 1 mol % or more to 20 mol % or less of one or more kinds of elements selected from B, Si, and C. A barrier layer including a material having a NaCl structure is formed between the crystalline underlayer and the magnetic layer.

What is claimed is: 
     
         1 . A magnetic recording medium comprising:
 a substrate;   a plurality of underlayers, including an uppermost underlayer, formed on the substrate;   a barrier layer formed on the uppermost underlayer; and   a magnetic layer formed on the barrier layer,   wherein a main component of the magnetic layer is an alloy having a L1 0  structure,   wherein at least one of the plurality of underlayers is a crystalline underlayer containing W,   wherein the W is a main component of the crystalline underlayer,   wherein the crystalline underlayer further contains 1 vol % or more to 50 vol % or less of an oxide, and   wherein the barrier layer includes a material having a NaCl structure.   
     
     
         2 . The magnetic recording medium as claimed in  claim 1 , wherein the oxide includes one or more oxides selected from B 2 O 3 , SiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO 2 , TiO, ZnO, La 2 O 3 , NiO, FeO, and CoO. 
     
     
         3 . The magnetic recording medium as claimed in  claim 1 ,
 wherein the plurality of underlayers includes an orientation control underlayer including one or more metals selected from Cr, an alloy having a BCC structure and including Cr as a main component, and an alloy having a B2 structure, and   wherein the crystalline underlayer is formed on the orientation control underlayer.   
     
     
         4 . The magnetic recording medium as claimed in  claim 1 , wherein the material having a NaCl structure includes one or more compounds selected from MgO, TiO, NiO, TiN, TiC, TaN, HfN, NbN, ZrC, HfC, TaC, and NbC. 
     
     
         5 . The magnetic recording medium as claimed in  claim 1 ,
 wherein the magnetic layer includes one or more substances selected from SiO 2 , TiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO, ZnO, B 2 O 3 , C, B, and BN,   wherein a main component of the magnetic layer is a FePt alloy having a L1 0  structure or a CoPt alloy.   
     
     
         6 . The magnetic recording medium as claimed in  claim 3 , wherein the crystalline underlayer is the uppermost underlayer. 
     
     
         7 . A magnetic storage apparatus comprising:
 the magnetic recording medium of  claim 1 .   
     
     
         8 . A magnetic recording medium comprising:
 a substrate;   an orientation control underlayer provided above the substrate;   a crystalline underlayer provided on the orientation control underlayer;   a barrier layer provided on the crystalline underlayer; and   a magnetic layer provided on the barrier layer,   wherein a main component of the magnetic layer is an alloy having a L1 0  structure,   wherein the orientation control underlayer is configured to control a crystal orientation of the magnetic layer to a (001) plane,   wherein the crystalline underlayer includes W as a main component, and 1 vol % or more to 50 vol % or less of one or more oxides selected from B 2 O 3 , SiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO 2 , TiO, ZnO, La 2 O 3 , NiO, FeO, and CoO, and   wherein the barrier layer includes a material having a NaCl structure.   
     
     
         9 . The magnetic recording medium as claimed in  claim 8 , further comprising:
 a seed layer, provided on the substrate, and made of NiTa,   wherein the orientation control underlayer is provided on the seed layer and is made of RuAl.   
     
     
         10 . The magnetic recording medium as claimed in  claim 8 , further comprising:
 a seed layer, provided on the substrate, and made of CrTi,   wherein the orientation control underlayer is provided on the seed layer and is made of CrMn.   
     
     
         11 . The magnetic recording medium as claimed in  claim 8 , further comprising:
 an adhesive layer, provided on the substrate, and made of CrTi;   a heat sink layer, provided on the adhesive layer, and made of CuZr; and   a seed layer, provided on the heat sink layer, and made of CrTi,   wherein the orientation control underlayer is provided on the seed layer and is made of CrRu.   
     
     
         12 . A magnetic storage apparatus comprising:
 the magnetic recording medium of  claim 8 .