Chemically ordered, cobalt-three platinum alloys for magnetic recording
View Patent ↗A magnetic recording layer having polycrystalline chemical ordered (COX) 3 Pt or (COX) 3 PtY alloys. The additive X comprises Sc, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Hf, Ta, W, Re, Os, B, or C, or any combination thereof. The additive Y comprises B, MgO, Al 2 O 3 , SiO 2 , P, CaO, CoO, B 2 O 3 , ZnO, NbO, Mo 2 O 3 , Co 2 O 3 , C, Cr, P, TiO 2 , Cr 2 O 3 , MnO, ZrO 2 , or BaO. The ratio of (CoX) to Pt is 2.33 to 4.00, plus or minus 5%. The additive Y may range from approximately 0 to 20% of the entire composition. The magnetic layer may be a constituent layer in a hard disc drive magnetic recording medium.
1. A magnetic recording layer consisting of hexagonal chemically ordered polycrystalline (CoX) z Pt phase alloy, wherein z ranges from 2.33 to 4.00, ±5%, and where X is selected from a group consisting of Sc, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Hf, Ta, W, Re, Os, B, and C, or any combination thereof.
2. The magnetic recording layer of claim 1 wherein Pt constitutes (25±5) atom % of the alloy, and CoX constitutes (75±5) atom % of the alloy; and further wherein Co constitutes from 65 atom % to 100 atom % and X ranges from greater than 0 atom % to 35 atom % of the CoX constituent of the alloy.
3. The magnetic recoding layer of claim 1 wherein the alloy is (CoCrX) z Pt.
4. The recording layer of claim 3 wherein Pt constitutes (25±5)% of the alloy and CoCrX constitutes (75±5)% of the alloy, and CoCrX has the formula
Co 100-x Cr x-y X y
where x and y are atom % of the sub composition, and where 0≦x≦35 and
0≦y≦5.
5. A magnetic recording medium having a magnetic layer comprising a hexagonal chemically ordered, polycrystalline phase alloy selected from the group consisting of (CoCrB) 3 Pt, (CoCrC) 3 Pt, (CoCrZr) 3 Pt, (CoCrHf) 3 Pt and (CoCrBCZrHf) 3 Pt.
6. A magnetic recording layer according to claim 1 further comprising an additive Y, where Y is selected from the group consisting of B, MgO, A 1 2 O 3 , SiO 2 , P, CaO, CoO, B 2 O 3 , ZnO, NbO, Mo 2 O 3 , Co 2 O 3 , C, Cr, P, TiO 2 , Cr 2 O 3 , MnO, ZrO 2 , and BaO, and where Y can be up to 20 atom % of the total composition.
7. A magnetic recording layer according to claim 2 further comprising an additive Y, where V is selected from the group consisting of B, MgO, Al 2 O 3 , SiO 2 , P, CaO,CoO, B 2 O 3 , ZnO, NbO, Mo 2 O 3 , Co 2 O 3 , C, Cr, P, TiO 2 , Cr 2 O 3 , MnO, ZrO 2 , and BaO, and where Y can be up to 20 atom % of the total composition.
8. A magnetic recording layer according to claim 4 further comprising an additive Y, where V is selected from the group consisting of B, MgO, Al 2 O 3 , SiO 2 , P, CaO, CoO, B 2 O 3 , ZnO, NbO, Mo 2 O 3 , Co 2 O 3 , C, Cr, P, TiO 2 , Cr 2 O 3 , MnO, ZrO 2 , and BaO, and where V can be up to 20 atom % of the total composition.
9. A magnetic recording medium comprising:
a substrate;
an interlayer composed of one or more layers, at least one layer having a non-magnetic alloy with an hcp structure; and
a magnetic recording layer consisting of hexagonal chemically ordered, polycrystalline (CoX) z Pt phase alloy, wherein z ranges from 2.33 to 4.00, ±5%, and where X is selected from a group consisting of Sc, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Hf, Ta, W, Re, Os, B, and C, or any combination thereof.
10. A magnetic recording medium according to claim 9 , wherein Pt constitutes (25±5)% of the alloy and CoX constitutes (75±5)% of the composition, and CoX has the formula
Co 100-x Cr x-y X y
where x and y are atom % of the sub composition, and where 0≦x≦35 and 0≦y≦5.
11. A magnetic recording medium according to claim 9 , further comprising:
an additive Y, where Y is selected from the group consisting of B, MgO, Al 2 O 3 , SiO 2 , P, CaO, CoO, B 2 O 3 , ZnO, NbO, Mo 2 O 3 , Co 2 O 3 , C, Cr, P, TiO 2 , Cr 2 O 3 , MnO, ZrO 2 , and BaO, and where Y can be up to 20% of the total composition.