Magnetic recording medium and producing method thereof

Abstract

To provide a magnetic recording medium with good record and reproduction characteristics. In the magnetic recording medium having an anodic oxidized alumina nanohole film filled with a magnetic substance, the anodic oxidized alumina nanohole film 13 is formed on a substrate 16 with at least one base electrode layer 15 sandwiched therebetween, the base electrode layer 15 is a film that has fcc structure and whose (111) face is oriented in the direction perpendicularly to a substrate, and the fillers 14 in the alumina nanoholes 10 have hcp structure and include hard magnetic substance whose principal component is Co and whose c-axis is perpendicular to the substrate.

1 . A magnetic recording medium, in which a mainly aluminum layer having holes on a substrate is filled with a magnetic substance, comprising: 
 at least one conductive layer between the mainly aluminum layer and the substrate,    wherein the magnetic substance contacts the conductive layer and the magnetic substance includes a hard magnetic substance that has hcp structure and the c-axes of which are oriented in a direction perpendicular to the substrate.    
     
     
         2 . The magnetic recording medium according to  claim 1 , wherein the hard magnetic substance includes Co.  
     
     
         3 . The magnetic recording medium according to  claim 2 , wherein the mainly aluminum layer has nanoholes formed by anodic oxidization.  
     
     
         4 . The magnetic recording medium according to  claim 1 , wherein the conductive layer is a base electrode layer.  
     
     
         5 . The magnetic recording medium according to  claim 1 , wherein the conductive layer includes Cu as a component.  
     
     
         6 . The magnetic recording medium according to  claim 1 , wherein a portion of each of the fillers with which the holes are filled, the portion which contacts the conductive layer, has fcc structure and its (111) face is oriented in a direction perpendicular to the substrate.  
     
     
         7 . The magnetic recording medium according to  claim 6 , wherein the portion touching the conductive layer includes Cu as a component.  
     
     
         8 . The magnetic recording medium according to  claim 6 , wherein the portion touching the conductive layer includes NiFe as a component.  
     
     
         9 . The magnetic recording medium according to  claim 2 , wherein the hard magnetic substance including Co includes at least one element among Cu, Cr, P, Ni, Pt, and Pd.  
     
     
         10 . The magnetic recording medium according to  claim 1 , wherein materials from the conductive layer to the hard magnetic substance are given epitaxial growth.  
     
     
         11 . The magnetic recording medium according to  claim 1 , wherein a soft magnetic substance layer is formed under the conductive layer.  
     
     
         12 . The magnetic recording medium according to  claim 1 , wherein the holes are arranged in a honeycomb array.  
     
     
         13 . The magnetic recording medium according to  claim 1 , wherein the holes are arranged in a rectangular array.  
     
     
         14 . A magnetic record and reproduction apparatus comprising the magnetic recording medium according to  claim 1 .  
     
     
         15 . A magnetic recording medium, in which an aluminum oxide layer having holes on a substrate is filled with a magnetic substance, comprising: 
 at least one conductive layer between the aluminum oxide layer and the substrate,    wherein the conductive layer has fcc structure and its (001) face is oriented in a direction perpendicular to the substrate, and the magnetic substance includes a hard magnetic substance that has L 1   0  structure and the c-axes of which are oriented in the direction perpendicular to the substrate.    
     
     
         16 . The magnetic recording medium according to  claim 15 , wherein the hard magnetic substance includes MPt (M=Co, Fe, Ni).  
     
     
         17 . The magnetic recording medium according to  claim 15 , wherein the conductive layer includes any one among Pt, Pd, Cu, Ir, and Rh.  
     
     
         18 . The magnetic recording medium according to  claim 15 , wherein a portion of each of the fillers with which the holes are filled, the portion which contacts the conductive layer, has fcc structure and its (001) face is oriented in a direction perpendicular to the substrate.  
     
     
         19 . The magnetic recording medium according to  claim 18 , wherein the portion contacting the conductive layer includes any one among Pt, Pd, Cu, Ir, and Rh.  
     
     
         20 . The magnetic recording medium according to  claim 16 , wherein the hard magnetic substance including MPt (M=Co, Fe, Ni) includes at least one element among Cu, Cr, P, Ag, and Pd.  
     
     
         21 . The magnetic recording medium according to  claim 16 , wherein materials from the conductive layer to the hard magnetic substance including MPt (M=Co, Fe, Ni) are given epitaxial growth.  
     
     
         22 . The magnetic recording medium according to  claim 15 , wherein an MgO (001) layer is formed under the conductive layer.  
     
     
         23 . The magnetic recording medium according to  claim 15 , wherein a soft magnetic substance layer is formed under the conductive layer.  
     
     
         24 . The magnetic recording medium according to  claim 15 , wherein the holes are arranged in a honeycomb array.  
     
     
         25 . The magnetic recording medium according to  claim 15 , wherein the holes are arranged in a rectangular array.  
     
     
         26 . A magnetic record and reproduction apparatus comprising the magnetic recording medium according to  claim 15 .  
     
     
         27 . A magnetic recording medium, in which an aluminum oxide layer having holes on a substrate is filled with a magnetic substance, comprising: 
 at least one conductive layer between the aluminum oxide layer and the substrate, wherein the conductive layer has any one of L 1   0 , L 1   1 , and L 1   2  ordered structures, and its square array face is oriented in a direction perpendicular to the substrate, and the magnetic substance includes a hard magnetic substance that has the L 1   0  structure and the c-axes of which are oriented in the direction perpendicular to the substrate.    
     
     
         28 . The magnetic recording medium according to  claim 27 , wherein the hard magnetic substance includes MPt (M=Co, Fe, Ni).  
     
     
         29 . The magnetic recording medium according to  claim 28 , wherein the conductive layer has any one among L 1   0  ordered structure including MPt (M=Co, Fe, Ni), L 1   1  ordered structure including CuPt, and L 1   2  ordered structure including CoPt 3 .  
     
     
         30 . The magnetic recording medium according to  claim 28 , wherein the hard magnetic substance including MPt (M=Co, Fe, Ni) includes at least one element among Cu, Cr, P, Ag, and Pd.  
     
     
         31 . The magnetic recording medium according to  claim 28 , wherein materials from the conductive layer to the hard magnetic substance including MPt (M=Co, Fe, Ni) are given epitaxial growth.  
     
     
         32 . The magnetic recording medium according to  claim 27 , wherein an MgO (001) layer is formed under the conductive layer.  
     
     
         33 . (Cancelled)  
     
     
         34 . The magnetic recording medium according to  claim 27 , wherein the holes are arranged in a honeycomb array.  
     
     
         35 . The magnetic recording medium according to  claim 27 , wherein the holes are arranged in a rectangular array.  
     
     
         36 . A magnetic record and reproduction apparatus comprising the magnetic recording medium according to  claim 27 .  
     
     
         37 . A method of manufacturing a magnetic recording medium that has a film with anodic oxidized alumina nanoholes filled with a magnetic substance, comprising: 
 a step of preparing a substrate;    a step of forming a conductive layer, which has fcc structure and its (111) face is oriented in a direction perpendicular to the substrate, on the substrate, and forming an alumina layer thereon;    a step of anodizing the alumina layer and forming alumina nanoholes; and    a step of electrodepositing a hard magnetic substance layer, which has hcp structure containing Co in the alumina nanoholes while the c-axes are oriented in a direction perpendicular to the substrate, in the alumina nanoholes.    
     
     
         38 . The method of manufacturing a magnetic recording medium according to  claim 37 , further comprising a step of electrodepositing a nonmagnetic layer, which has fcc structure including Cu and whose (111) face is oriented in a direction perpendicular to the substrate, before the step of electrodepositing the hard magnetic substance layer.  
     
     
         39 . The method of manufacturing a magnetic recording medium according to  claim 37 , further comprising a step of electrodepositing a soft magnetic layer, which has fcc structure mainly including NiFe and whose (111) face is oriented in a direction perpendicular to the substrate, before the step of electrodepositing the hard magnetic substance layer.  
     
     
         40 . A method of manufacturing a magnetic recording medium that has a film with anodic oxidized alumina nanoholes filled with a magnetic substance comprising: 
 a step of preparing a substrate;    a step of forming a conductive layer, which has fcc structure and whose (001) face is oriented in a direction perpendicular to the substrate, and an alumina layer on the substrate;    a step of forming alumina nanoholes by anodizing the alumina layer;    a step of electrodepositing a layer including Mpt (M=Co, Fe, Ni) in each of the alumina nanoholes; and    a step of formation of hard magnetic substance oriented the c-axes in a direction perpendicular to the substrate in L 1   0  ordered structure by annealing process.    
     
     
         41 . A method of manufacturing a magnetic recording medium that has a film with anodic oxidized alumina nanoholes filled with a magnetic substance comprising: 
 a step of preparing a substrate;    a step of forming a conductive layer, which has any one of L 1   0 , L 1   1 , and L 1   2  ordered structure, and a square lattice face of which is oriented in a direction perpendicular to the substrate, and an alumina layer on the substrate;    a step of anodizing the alumina layer and forming alumina nanoholes;    a step of electrodepositing a layer including Mpt (M=Co, Fe, Ni) in each of the alumina nanoholes; and    a step of formation of hard magnetic substance oriented the c-axes in a direction perpendicular to the substrate in L 1   0  ordered structure by annealing process.    
     
     
         42 . The method of manufacturing a magnetic recording medium according to  claim 40 , further comprising a step of electrodepositing a nonmagnetic layer, which has fcc structure including any one among Pt, Pd, Cu, Ir, and Rh, and whose (001) face is oriented in a direction perpendicular to the substrate, before the step of electrodepositing the layer including Mpt (M=Co, Fe, Ni) in each of the alumina nanoholes.  
     
     
         43 . The method of manufacturing a magnetic recording medium according to  claim 41 , further comprising a step of electrodepositing a soft magnetic layer, which has fcc structure mainly including NiFe and whose (001) face is oriented in a direction perpendicular to the substrate, before the step of electrodepositing the layer including Mpt (M=Co, Fe, Ni) in each of the alumina nanoholes.  
     
     
         44 . The magnetic recording medium according to  claim 1 , wherein the conductive layer has fcc structure and its (111) face is oriented in a direction perpendicular to the substrate.  
     
     
         45 . The magnetic recording medium according to  claim 1 , wherein the layer is an alumina oxide layer.