# US 5,700,593 A · Metal thin film magnetic recording medium and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,593 A - Document ID: US5700593A - Status: Granted - Kind: A - Application number: 08/206,849 - Filed: 1994-03-07 - Granted: 1997-12-23 - Earliest claimed: 1993-06-23 - Assignees: Kubota Corporation - Inventors: Yoshinobu Okumura; Xingbo Yang - Web page: https://patentgrep.com/patent/US5700593A ## CPC - G11B 5/656: {containing Co (containing inorganic, non-oxide compounds of Si, N, P, B, H or C G11B5/657; containing oxygen G11B5/658)} - G11B 5/7369: {Two or more non-magnetic underlayers, e.g. seed layers or barrier layers} - G11B 5/7379: {Seed layer, e.g. at least one non-magnetic layer is specifically adapted as a seed or seeding layer} - Y10S 428/90: Magnetic feature - Y10S 428/91: Product with molecular orientation - Y10T 428/265: 1 mil or less - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A metal thin film magnetic recording medium comprising an underlying non-magnetic layer and a magnetic layer comprising a Co-alloy having a uni-axial magnetocrystalline anisotropy formed in this order by lamination on the surface of a non-magnetic substrate. On the substrate, are formed a seed layer comprising an oxygen-containing non-magnetic amorphous metal or a seed layer comprising a non-magnetic amorphous metal having an oxygen-containing layer (not illustrated) on the surface, and an underlying non-magnetic layer is laminated on the seed layer. Further, a seed layer comprising an amorphous Cr- or V-alloy is formed on the substrate, and an underlying non-magnetic layer is laminated on the seed layer. ## Claims ### Claim 1 A metal thin film magnetic recording medium, comprising: (i) a non-magnetic substrate; (ii) a seed layer on said substrate; (iii) an underlying non-magnetic layer, comprising Cr, on said seed layer; and (iv) a magnetic layer, comprising a Co-alloy having a uni-axial magnetocrystalline anisotropy, on said underlying non-magnetic layer; wherein said seed layer comprises an oxygen-containing non-magnetic metal and said oxygen-containing non-magnetic metal is amorphous as determined by X-ray diffraction. ### Claim 2 (depends on 1) A metal thin film magnetic recording medium as defined in claim 1, wherein the thickness of the seed layer is greater than 100 .ANG.. ### Claim 3 (depends on 1) A metal thin film magnetic recording medium as defined in claim 1, wherein the seed layer is an oxygen-containing amorphous Cr-alloy or V-alloy. ### Claim 4 (depends on 1) A metal thin film magnetic recording medium as defined in claim 1, wherein a protection layer is laminated on the magnetic layer. ### Claim 5 (depends on 4) A metal thin film magnetic recording medium as defined in claim 4, wherein a lubrication layer is laminated on the protection layer. ### Claim 6 (depends on 1) A metal thin film magnetic recording medium as defined in claim 1, further comprising (v) another non-magnetic layer comprising Cr, adjacent to said magnetic layer. ### Claim 7 A metal thin film magnetic recording medium, comprising: (i) a non-magnetic substrate; (ii) a seed layer on said substrate; (iii) an underlying non-magnetic layer, comprising Cr, on said seed layer; and (iv) a magnetic layer, comprising a Co-alloy having a uni-axial magnetocrystalline anisotropy, on said underlying non-magnetic layer; wherein said seed layer comprises a non-magnetic metal alloy, said alloy is amorphous as determined by X-ray diffraction, and the surface of said non-magnetic alloy, opposite said substrate, contains oxygen. ### Claim 8 (depends on 7) A metal thin film magnetic recording medium as defined in claim 7, wherein the thickness of the seed layer is greater than 100 .ANG.. ### Claim 9 (depends on 7) A metal thin film magnetic recording medium as defined in claim 7, wherein the seed layer is an oxygen-containing amorphous Cr-alloy or V-alloy. ### Claim 10 (depends on 7) A metal thin film magnetic recording medium as defined in claim 7, wherein a protection layer is laminated on the magnetic layer. ### Claim 11 (depends on 10) A metal thin film magnetic recording medium as defined in claim 10, wherein a lubrication layer is laminated on the protection layer. ### Claim 12 (depends on 7) A metal thin film magnetic recording medium as defined in claim 7, further comprising (v) another non-magnetic layer comprising Cr, adjacent to said magnetic layer. ### Claim 13 A metal thin film magnetic recording medium, comprising: (i) a non-magnetic substrate; (ii) a seed layer on said substrate; (iii) an underlying non-magnetic layer, comprising Cr, on said seed layer; and (iv) a magnetic layer, comprising a Co-alloy having a uni-axial magnetocrystalline anisotropy, on said underlying non-magnetic layer; wherein said seed layer comprises an Cr-alloy or V-alloy, both said Cr-alloy and V-alloy comprising at least one element selected from the group consisting of Ta, Nb, Si, Al and C, and said Cr-alloy or V-alloy is amorphous as determined by X-ray diffraction. ### Claim 14 (depends on 13) A metal thin film magnetic recording medium as defined in claim 13, wherein the thickness of the seed layer is greater than 100 .ANG.. ### Claim 15 (depends on 13) A metal thin film magnetic recording medium as defined in claim 13, wherein the Cr- or V-alloy is an alloy containing Ta. ### Claim 16 (depends on 13) A metal thin film magnetic recording medium as defined in claim 13, wherein a protection layer is laminated on the magnetic layer. ### Claim 17 (depends on 16) A metal thin film magnetic recording medium as defined in claim 16, wherein a lubrication layer is laminated on the protection layer. ### Claim 18 (depends on 13) A metal thin film magnetic recording medium as defined in claim 13, further comprising (v) another non-magnetic layer comprising Cr, adjacent to said magnetic layer. ### Claim 19 A metal thin film magnetic recording medium, comprising: (i) a non-magnetic substrate; (ii) a seed layer on said substrate; (iii) an underlying non-magnetic layer, comprising Cr, on said seed layer; and (iv) a magnetic layer, comprising a Co-alloy having a uni-axial magnetocrystalline anisotropy, on said underlying non-magnetic layer; wherein said seed layer comprises a Cr-alloy or V-alloy comprising at least 40 at % Cr or V, and said Cr-alloy or V-alloy is amorphous as determined by X-ray diffraction.