MAGNETIC RECORDING MEDIUM, METHOD FOR MANUFACTURING THE SAME, AND MAGNETIC RECORDING APPARATUS
According to an aspect of an embodiment, a magnetic recording medium includes a soft under layer, a seed layer containing an alloy, placed over the soft under layer, a ruthenium containing layer containing crystalline Ru, directly placed on the seed layer, and a recording layer placed over the ruthenium containing layer. The alloy contains metal atoms bonded to one another with a minimum distance of adjacent atoms. The difference between the minimum distance of the atoms in the alloy and that of the atoms in the crystalline Ru is 2% or less.
1 . A magnetic recording medium comprising:
a soft under layer,
a seed layer containing an alloy, placed over the soft under layer,
a ruthenium containing layer containing crystalline Ru, directly placed on the seed layer, and
a recording layer placed over the ruthenium containing layer, the alloy containing metal atoms bonded to one another with a minimum distance of adjacent atoms, the crystalline Ru containing metal atoms bonded to one another with a minimum distance, the difference between the minimum distance of the alloy and that of the crystalline Ru being 2% or less.
2 . The magnetic recording medium according to claim 1 , wherein the recording layer has a cubic close-packed crystal structure and the seed layer has a face-centered cubic crystal structure.
3 . The magnetic recording medium according to claim 1 , wherein the recording layer has a surface to which (0002) plane of the crystalline Ru is oriented and the seed layer has a surface to which (111) plane of the alloy is oriented.
4 . The magnetic recording medium according to claim 1 , wherein the seed layer contains at least two elements selected from the group consisting of Ni, Pt, and Pd.
5 . The magnetic recording medium according to claim 1 , wherein the seed layer contains Ni—Pt or Ni—Pd.
6 . The magnetic recording medium according to claim 5 , wherein a content of Ni in the seed layer is 20 to 80 atomic percent.
7 . The magnetic recording medium according to claim 5 , wherein a content of Ni in the seed layer is 30 to 60 atomic percent.
8 . The magnetic recording medium according to claim 5 , wherein a content of Ni in the seed layer is 40 to 60 atomic percent.
9 . The magnetic recording medium according to claim 1 , wherein the seed layer contains at least one selected from the group consisting of Cu—Pd, Cu—Pt, Ni—Au, Cu—Au, and Cu—Al.
10 . The magnetic recording medium according to claim 9 , wherein the seed layer contains at least one selected from the group consisting of SiO 2 , TiO 2 , Cr, B, Zr, Ta, W, Mn, C and Nb with the content below 20 atomic percent.
11 . The magnetic recording medium according to claim 1 , wherein the recording layer contains Co and Pt.
12 . The method according to claim 11 , wherein the recording layer further contains at least one selected from the group consisting of Cr, B, SiO 2 , TiO 2 , CrO 2 , CrO, Cu, Ti, CoO, Mn, W, and Nb.
13 . A method for making a magnetic recording medium comprising the steps of:
forming a soft under layer,
forming a seed layer containing an alloy over the soft under layer,
forming a ruthenium containing layer containing crystalline Ru directly on the seed layer, and
forming a recording layer over the ruthenium containing layer, the alloy containing metal atoms bonded to one another with a minimum distance of adjacent atoms, the difference between the minimum distance of the alloy and that of the crystalline Ru being 2% or less.
14 . The method according to claim 13 , wherein the recording layer has a cubic close-packed crystal structure, and the seed layer has a face-centered cubic crystal structure.
15 . The method according to claim 13 , the recording layer has a surface to which (0002) plane of the crystalline Ru is oriented and the seed layer has a surface to which (111) plane of the alloy is oriented.
16 . The method according to claim 13 , wherein the seed layer contains at least two elements selected from the group consisting of Ni, Pt, and Pd.
17 . The method according to claim 13 , wherein the seed layer contains Ni—Pt or Ni—Pd.
18 . The method according to claim 13 , wherein the recording layer contains Co and Pt.
19 . A magnetic recording apparatus comprising:
a magnetic recording medium including:
a soft under layer,
a seed layer containing an alloy, placed over the soft under layer,
a ruthenium containing layer containing crystalline Ru, directly placed on the seed layer, and
a recording layer placed over the ruthenium containing layer, the alloy containing metal atoms bonded to one another with a minimum distance of adjacent atoms, the crystalline Ru containing metal atoms bonded to one another with a minimum distance, the difference between the minimum distance of the alloy and that of the crystalline Ru being 2% or less; and
a magnetic head facing the magnetic recording medium for reading and writing information from and on the magnetic recording medium.