US5236791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium and magnetic storage
Assignee: HGST Japan Ltd
•
Filing: 1989-08-28
•
Granted: 1993-08-17
•
Expires: 2009-08-28
Abstract
Abstract A magnetic recording medium that uses, as a protective coating layer provided on a magnetic layer for magnetically recording signals, a layer made of a nonmagnetic material consisting of two ore more elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and one or more elements of N, C, O, and B, or made of a magnetic material consisting of one or more elements of Co, Fe, Ni, and Gd, one or more elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and one or more elements of N, C, O, B, and Si is excellent in sliding endurance. When the protective coating layer is made of the nonmagnetic material, the magnetic recording medium is also excellent in corrosion resistance, and when the protective coating layer is made of the magnetic material, the spacing between a magnetic head and the magnetic recording medium can advantageously be made large. Both the cases are high in reliability, and suitable for high density magnetic recording. The magnetic recording medium can be used in combination with a magnetic head that uses a metal magnetic alloy as at least part of the magnetic core to provide an excellent magnetic storage.
Inventors
- 👤 Yotsuo Yahisa
- 👤 Yoshihiro Shiroishi
- 👤 Sadao Hishiyama
- 👤 Tomoyuki Ohno
- 👤 Shinichiro Saitoh
- 👤 Suzuki Hiroyuki
- 👤 Yoshibumi Matsuda
- 👤 Norikazu Tsumita
- 👤 Masaki Ohura
- 👤 Noriyuki Shige
- 👤 Kazumasa Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:14
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12535; Y10T428/12542; Y10T428/12576; Y10T428/12583; Y10T428/1259; Y10T428/12611; Y10T428/1266; Y10T428/12674; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854; Y10T428/12861; Y10T428/12875; Y10T428/12931
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
96 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer consisting essentially of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 2
Dependent Claim
96 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer consisting essentially of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 3
Dependent Claim
46 words
The magnetic recording medium as claimed in claim 1, wherein the content of one element of said first group is from 0.1 at. % to up to 99.9 at. %, assuming the total amount of the elements of the first group to be 100 at. %.
Claim 4
Dependent Claim
51 words
The magnetic recording medium as claimed in claim 1, wherein the total amount of the elements of the first group is from 10 at. % to up to 99 at. %, assuming the total amount of the elements of the first group, and the second group to be 100 at. %.
Claim 5
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 1, wherein said nonmagnetic protective coating layer contains at least Zr, Hf, or Nb.
Claim 6
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 1, wherein said nonmagnetic protective coating layer contains at least W.
Claim 7
Dependent Claim
59 words
The magnetic recording medium as claimed in claim 1, wherein said nonmagnetic protective coating layer contains further at least one element selected from the group consisting of Y, Mg, Ca, Al, and Si in an amount of from 0.1 at. % to up to 20 at. % based on the total amount of the elements of the first group.
Claim 8
Dependent Claim
27 words
The magnetic recording medium as claimed in claim 1, wherein the thickness of said nonmagnetic protective coating layer is from 5 nm to up to 60 nm.
Claim 9
Dependent Claim
29 words
The magnetic recording medium as claimed in claim 1, wherein a nonmagnetic intermediate metal layer is positioned between said nonmagnetic protective coating layer and said magnetic continuous thin film.
Claim 10
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 4, wherein said nonmagnetic protective coating layer contains at least N.
Claim 11
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 5, wherein said nonmagnetic protective coating layer contains at least N.
Claim 12
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 5, wherein said nonmagnetic protective coating layer contains at least C.
Claim 13
Dependent Claim
101 words
The magnetic recording medium as claimed in claim 8, wherein said nonmagnetic intermediate metal layer contains at least one element selected from a group consisting of Pt, Pd, Rh, Ir, Ru, and Os in an amount of from down to 0.01 at. % to up to 1 at. % in all, or at least one element selected from a group consisting of Mo and Ni in an amount of from down to 0.1 wt. % to up to 1 st. % in all, and the balance of one element selected from a group consisting of Ti, Zr, Hf, Nb, and Ta.
Claim 14
Dependent Claim
58 words
The magnetic recording medium as claimed in claim 8, wherein said nonmagnetic intermediate metal layer consists of an Ni alloy containing from down to 1 wt. % to up to 40 wt. % of at least one element selected from a group consisting of Ti, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Cu, Al, and Si.
Claim 15
Dependent Claim
27 words
The magnetic recording medium as claimed in claim 8, wherein the thickness of said nonmagnetic intermediate metal layer is from 2 nm to up to 15 nm.
Claim 16
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 13, wherein said nonmagnetic intermediate metal layer consists of an Ni alloy containing from 27 wt. % to up to 34 wt. % of Cu.
Claim 17
Dependent Claim
46 words
The magnetic recording medium as claimed in claim 13, wherein said nonmagnetic intermediate metal layer consists of an Ni alloy containing from 2 wt. % to up to 32 wt. % of Mo, and from 13 wt. % to up to 25 wt. % of Cr.
Claim 18
Dependent Claim
95 words
The magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer consisting essentially of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 19
Dependent Claim
95 words
The magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer consisting essentially of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 20
Dependent Claim
130 words
The magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and C wherein the composition of said nonmagnetic protective coating is substantially homogeneous from one face side through the opposite face side and wherein said at least two elements selected from said first group contain at least a pair of elements selected from the group consisting of Ti-V, Ti-Nb, Ti-Cr, Ti-Mo, Zr-Hf, Zr-Nb, Zr-Ta, Zr-Cr, Zr-Mo, Zr-W, Hf-Nb, Hf-Ta, Hf-Cr, Hf-Mo, Hf-W, V-Nb, V-Ta, V-Cr, V-Mo, V-W, Nb-Ta, Nb-Cr, Nb-Mo, Nb-W, Ta-Cr, and Ta-Mo.
Claim 21
Dependent Claim
130 words
The magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and C wherein the composition of said nonmagnetic protective coating is substantially homogeneous from one face side through the opposite face side and wherein said at least two elements selected from said first group contain at least a pair of elements selected from the group consisting of Ti-V, Ti-Nb, Ti-Cr, Ti-Mo, Zr-Hf, Zr-Nb, Zr-Ta, Zr-Cr, Zr-Mo, Zr-W, Hf-Nb, Hf-Ta, Hf-Cr, Hf-Mo, Hf-W, V-Nb, V-Ta, V-Cr, V-Mo, V-W, Nb-Ta, Nb-Cr, Nb-Mo, Nb-W, Ta-Cr, and Ta-Mo.
Claim 22
Dependent Claim
93 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said continuous thin film, said nonmagnetic protective coating layer comprising at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, C, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 23
Dependent Claim
93 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said continuous thin film, said nonmagnetic protective coating layer comprising at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, C, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 24
Dependent Claim
46 words
The magnetic recording medium as claimed in claim 19, wherein the content of one element of said first group is from 0.1 at. % to up to 99.9 at. %, assuming the total amount of the elements of the first group to be 100 at. %.
Claim 25
Dependent Claim
51 words
The magnetic recording medium as claimed in claim 19, wherein the total amount of the elements of the first group is from 10 at. % to up to 99 at. %, assuming the total amount of the elements of the first group, and the second group to be 100 at. %.
Claim 26
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 19, wherein said nonmagnetic protective coating layer contains at least Zr, Hf, or Nb.
Claim 27
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 19, wherein said nonmagnetic protective coating layer contains at least W.
Claim 28
Dependent Claim
58 words
The magnetic recording medium as claimed in claim 19, wherein said nonmagnetic protective coating layer further at least one element selected from the group consisting of Y, Mg, Ca, Al, and Si in an amount of from 0.1 at. % to up to 20 at. % based on the total amount of the elements of the first group.
Claim 29
Dependent Claim
29 words
The magnetic recording medium as claimed in claim 19, wherein the thickness of said nonmagnetic protective coating layer is from down to 5 nm to up to 60 nm.
Claim 30
Dependent Claim
29 words
The magnetic recording medium as claimed in claim 19, wherein a nonmagnetic intermediate metal layer is positioned between said nonmagnetic protective coating layer and said magnetic continuous thin film.
Claim 31
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 22, wherein said nonmagnetic protective coating layer contains at least N.
Claim 32
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 23, wherein said nonmagnetic protective coating layer contains at least N.
Claim 33
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 23, wherein said nonmagnetic protective coating layer contains at least C.
Claim 34
Dependent Claim
97 words
The magnetic recording medium as claimed in claim 26, wherein said nonmagnetic intermediate metal layer contains at least one element selected from a group consisting of Pt, Pd, Rh, Ir, Ru, and Os in an amount of from 0.01 at. % to up to 1 at. % in all, or at least one element selected from a group consisting of Mo and Ni in an amendment of from 0.1 wt. % to up to 1 wt. % in all, and the balance of one element selected from a group consisting of Ti, Zf, Hf, Nb, and Ta.
Claim 35
Dependent Claim
56 words
The magnetic recording medium as claimed in claim 26, wherein said nonmagnetic intermediate metal layer consists of an Ni alloy containing from 1 wt. % to up to 40 wt. % of at least one element selected from a group consisting of Ti, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Cu, Al, and Si.
Claim 36
Dependent Claim
27 words
The magnetic recording medium as claimed in claim 26, wherein the thickness of said nonmagnetic intermediate metal layer is from 2 nm to up to 15 nm.
Claim 37
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 31, wherein said nonmagnetic intermediate metal layer consists of an Ni alloy containing from 27 wt. % to up to 34 wt. % of Cu.
Claim 38
Dependent Claim
44 words
The magnetic recording medium as claimed in claim 31, said nonmagnetic intermediate metal layer consisting of an Ni alloy containing from 2 wt. % to up to 32 st. % of Mo, and 13 wt. % to up to 25 wt. % of Cr.
Claim 39
Dependent Claim
93 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at lesat two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 40
Dependent Claim
93 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at lesat two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, O, and B wherein the composition of said nonmagnetic protective coating layer is substantially homogeneous from one face side through the opposite face side.
Claim 41
Dependent Claim
93 words
A composite magnetic recording medium having at least two magnetic continuous thin films and having a nonmagnetic support for said magnetic continuous thin films, the first magnetic continuous thin film on the information recording side consisting essentially of at least one element selected from a first group consisting of Co, Fe, N, and Gd, at least one element selected from a second group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a third group consisting of N, C, O, B, and Si.
Claim 42
Dependent Claim
93 words
A composite magnetic recording medium having at least two magnetic continuous thin films and having a nonmagnetic support for said magnetic continuous thin films, the first magnetic continuous thin film on the information recording side consisting essentially of at least one element selected from a first group consisting of Co, Fe, N, and Gd, at least one element selected from a second group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a third group consisting of N, C, O, B, and Si.
Claim 43
Dependent Claim
41 words
The magnetic recording medium as claimed in claim 36, wherein the all the magnetic continuous thin films constituting said composite magnetic thin film are joined magnetically, and are magnetized and reversed with the same coercive force against the external magnetic field.
Claim 44
Dependent Claim
62 words
The magnetic recording medium as claimed in claim 36, said magnetic recording medium having the first magnetic continuous thin film wherein the total amount of the elements of the second group is from 3 at. % to up to 60 at. %, assuming the total amount of the elements of the first group, and the second group to be 100 at. %.
Claim 45
Dependent Claim
62 words
The magnetic recording medium as claimed in claim 36, said magnetic recording medium having the first magnetic continuous thin film wherein the total amount of the elements of the third group is from 6 at. % to up to 80 at. %, assuming the total amount of the elements of the first group, and the second group to be 100 at. %.
Claim 46
Dependent Claim
28 words
The magnetic recording medium as claimed in claim 36, wherein the thickness of said first magnetic continuous thin film is from 5 nm to up to 100 nm.
Claim 47
Dependent Claim
24 words
The magnetic recording medium as claimed in claim 36, wherein an organic lubricating film is provided directly on said first magnetic continuous thin film.
Claim 48
Dependent Claim
125 words
A magnetic storage device, comprising (i) at least one magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer being made up of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B, and (ii) a magnetic head having a metal magnetic alloy as at least part of a magnetic core, and said magnetic head being provided in such a position that signals can be recorded in or reproduced from said magnetic recording medium.
Claim 49
Dependent Claim
125 words
A magnetic storage device, comprising (i) at least one magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer being made up of at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B, and (ii) a magnetic head having a metal magnetic alloy as at least part of a magnetic core, and said magnetic head being provided in such a position that signals can be recorded in or reproduced from said magnetic recording medium.
Claim 50
Dependent Claim
90 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two layers which are different in composition from each other and each of which comprises at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B.
Claim 51
Dependent Claim
90 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two layers which are different in composition from each other and each of which comprises at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least one element selected from a second group consisting of N, C, O, and B.
Claim 52
Dependent Claim
90 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two layers which are different in composition from each other and each of which comprises at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, C, O, and B.
Claim 53
Dependent Claim
90 words
A magnetic recording medium having at least one nonmagnetic protective coating layer on a magnetic continuous thin film and having a nonmagnetic support for said magnetic continuous thin film, said nonmagnetic protective coating layer comprising at least two layers which are different in composition from each other and each of which comprises at least two elements selected from a first group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, and at least two elements selected from a second group consisting of N, C, O, and B.
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