MAGNETIC RECORDING MEDIUM, METHOD FOR MANUFACTURING MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING AND REPRODUCING DEVICE

1 . A magnetic recording medium in which, on a non-magnetic substrate, at least an orientation control layer that controls orientation of a layer immediately above and a vertical magnetic layer in which an easy axis of magnetization is mainly vertically oriented with respect to the non-magnetic substrate are laminated,

wherein the orientation control layer includes an Ru-containing layer containing Ru or Ru alloy, and a diffusion prevention layer that is provided on the Ru-containing layer on the side of the vertical magnetic layer, is made of a material having a melting point of 1500° C. or higher and 4215° C. or lower, and is formed by a covalent bond or an ionic bond and prevents thermal diffusion of Ru atoms in the Ru-containing layer, and

the vertical magnetic layer has a crystalline structure of crystal grains that is continuously formed from the Ru-containing layer with the diffusion prevention layer interposed therebetween and includes a columnar crystal that is continuously formed in a thickness direction together with the crystal grains.

2 . The magnetic recording medium according to claim 1 ,

wherein the Ru-containing layer includes a first Ru-containing layer and a second Ru-containing layer disposed on the first Ru-containing layer on the side of the vertical magnetic layer,

the first Ru-containing layer includes crystalline structure as a nucleus of columnar crystalline structure, and

the second Ru-containing layer includes columnar crystalline structure continuously formed in the thickness direction to the crystal that is the nucleus and is formed with a dome-shaped convex part at the top thereof.

3 . The magnetic recording medium according to claim 1 ,

wherein a second diffusion prevention layer made of a material having a melting point of 1500° C. or higher and 4215° C. or lower and formed by a covalent bond or an ionic bond and prevents the thermal diffusion of the Ru atoms of the Ru-containing layer is provided on the Ru-containing layer on the side of the non-magnetic substrate.

4 . The magnetic recording medium according to claim 2 ,

wherein an intermediate diffusion prevention layer made of a material having a melting point of 1500° C. or higher and 4215° C. or lower and formed by a covalent bond or an ionic bond and prevents the thermal diffusion of the Ru atoms of the Ru-containing layer is provided between the first Ru-containing layer and the second Ru-containing layer.

5 . The magnetic recording medium according to claim 1 ,

wherein the diffusion prevention layer includes any one selected from a group including AlN, SiO 2 , MgO, Ta 2 O 5 , Cr 2 O 3 and ZrO 2 .

6 . The magnetic recording medium according to claim 1 ,

wherein a soft magnetic underlayer is provided on the orientation control layer on the side of the non-magnetic substrate.

7 . The magnetic recording medium according to claim 1 ,

wherein the vertical magnetic layer includes an alloy having an L1 0 crystalline structure as a main component.

8 . A method for manufacturing a magnetic recording medium, comprising:

an orientation control layer forming process of forming an orientation control layer that controls orientation of a layer immediately above on a non-magnetic substrate; and

a vertical magnetic layer forming process of forming, on the non-magnetic substrate, a vertical magnetic layer in which an easy axis of magnetization is mainly vertically oriented with respect to the non-magnetic substrate,

wherein the orientation control layer forming process includes a process of forming an Ru-containing layer containing Ru or Ru alloy, and a process of forming, on the Ru-containing layer, a diffusion prevention layer made of a material having a melting point of 1500° C. or higher and 4215° C. or lower and formed by a covalent bond or an ionic bond and prevents thermal diffusion of Ru atoms of the Ru-containing layer, and

the vertical magnetic layer forming process includes a heating process of heating the non-magnetic substrate at 300° C. to 700° C. immediately before the start of formation of the vertical magnetic layer and/or during the formation to form the vertical magnetic layer that has a crystalline structure of crystal grains continuously formed from the Ru-containing layer with the diffusion prevention layer interposed therebetween and includes a columnar crystal continuously formed in a thickness direction together with the crystal grains.

9 . The method for manufacturing a magnetic recording medium according to claim 8 ,

wherein, in the process of forming the diffusion prevention layer, the diffusion prevention layer that includes any one selected from a group including AlN, SiO 2 , MgO, Ta 2 O 5 , Cr 2 O 3 and ZrO 2 is formed.

10 . The method for manufacturing a magnetic recording medium according to claim 8 ,

wherein a process of forming a soft magnetic underlayer on the non-magnetic substrate is performed before the orientation control layer forming process.

11 . A magnetic recording and reproducing device comprising:

the magnetic recording medium according to claim 1 ;

a medium drive unit that drives the magnetic recording medium in a recording direction;

a magnetic head that performs a recording operation and a reproducing operation with respect to the magnetic recording medium;

a head drive unit that relatively moves the magnetic head with respect to the magnetic recording medium; and

a recording and reproducing signal-processing system that performs input of a signal to the magnetic head and reproduction of an output signal from the magnetic head.

12 . The magnetic recording and reproducing device according to claim 11 ,

wherein the magnetic head includes a laser generating unit that heats the magnetic recording medium, a wave guide that guides laser light generated from the laser generating unit to a tip portion thereof, and a near-field generating element provided at the tip portion.