Perpendicular magnetic recording medium and magnetic recording apparatus

• US 6,562,453 B1
• Filed: 07/05/2000
• Issued: 05/13/2003
• Est. Priority Date: 07/06/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Japan Limited (Western Digital Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Hirayama, Yoshiyuki, Futamoto, Masaaki, Honda, Yukio, Kikukawa, Atsushi
• Primary Examiner(s): RICKMAN, HOLLY C
• Application Number:
  US09/610,455
• Time in Patent Office: 1,042 Days
• Field of Search: 428/694.TM, 428/694.TS, 428/900, 428/694.TB, 428/336, 428/332, 428/611, 360/97.01
• US Class Current: 428/332
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11B 2005/001 Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
• CPC Class Codes: G11B 2005/0016 of magnetoresistive transducers
• CPC Class Codes: G11B 2005/0029 using magnetisation components of the recording layer disposed mainly perpendicularly to the record carrier surface
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/00 Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor G11B11/00 and G11B13/00 take precedence
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/676 having magnetic layers separated by a nonmagnetic layer, e.g. antiferromagnetic layer, Cu layer or coupling layer
• CPC Class Codes: G11B 5/737 Physical structure of underlayer, e.g. texture
• CPC Class Codes: G11B 5/7377 Physical structure of underlayer, e.g. texture
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/12465 having magnetic properties, or preformed fiber orientation coordinate with shape
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

To provide an improved perpendicular magnetic recording medium suitable for high density magnetic recording. In a perpendicular magnetic recording medium comprising a perpendicular magnetic layer and protective layer provided on a non-magnetic substrate via a soft magnetic backlayer, a polycrystalline MgO film is inserted between the soft magnetic backlayer and perpendicular magnetic layer.

Claims

1. A perpendicular magnetic recording medium wherein a perpendicular magnetic layer is provided on a non-magnetic substrate via a soft magnetic backlayer, wherein a polycrystalline MgO film is inserted between said soft magnetic backlayer and said perpendicular magnetic layer, and the perpendicular magnetic layer formed on said polycrystalline MgO film has a hexagonal close-packed structure, wherein a distance between a surface of said soft magnetic backlayer and said perpendicular magnetic layer is within 20 nm.

3. A perpendicular magnetic recording medium according to claim 1, wherein a non-magnetic layer comprising a material comprising Ti, Zr, Hf, Cr, Mo, Nb, V, W, Si, Ge, B, C or alloys having these elements as their main component, or oxides selected from the group consisting of SiO₂, Al₂O₃ or ZrO₂, is provided between said soft magnetic backlayer and said polycrystalline MgO film.

6. A perpendicular magnetic recording medium according to claim 3, wherein the total film thickness of the non-magnetic layer formed between said soft magnetic backlayer and said perpendicular magnetic layer is from 2 nm to less than 20 nm, and the thickness of said polycrystalline MgO film is from 1 nm to less than 13 nm.

2. A perpendicular magnetic recording medium wherein a perpendicular magnetic layer is provided on a non-magnetic substrate via a soft magnetic backlayer, wherein a polycrystalline MgO film is provided on said soft magnetic backlayer, a non-magnetic layer having a hexagonal close-packed structure is provided on said polycrystalline MgO film, the perpendicular magnetic layer is provided on said non-magnetic layer, and said perpendicular magnetic layer has a hexagonal close-packed structure, wherein a distance between a surface of said soft magnetic backlayer and said perpendicular magnetic layer is within 20 nm.

4. A perpendicular magnetic recording medium according to claim 2, wherein a non-magnetic layer comprising a material comprising Ti, Zr, Hf, Cr, Mo, Nb, V, W, Si, Ge, B, C or alloys having these elements as their main component, or oxides selected from the group consisting of SiO₂, Al₂O₃ or ZrO₂, is provided between said soft magnetic backlayer and said polycrystalline MgO film.

5. A perpendicular magnetic recording medium according to claim 2, wherein the thickness of said polycrystalline MgO film is from 1 nm to less than 13 nm.

7. A magnetic recording apparatus comprising a magnetic recording medium, a magnetic recording medium drive unit which drives said magnetic recording medium, a magnetic head which performs recording and reproduction on said magnetic recording medium, a magnetic head drive unit which drives said magnetic head, and a recording/reproduction signal processing system which processes recording signals and reproduction signals sent to and from said magnetic head, wherein said magnetic recording medium comprises a soft magnetic backlayer provided on a non-magnetic substrate, a polycrystalline MgO film formed on said soft magnetic backlayer, and a perpendicular magnetic layer having a hexagonal close-packed structure provided on said polycrystalline MgO film, said magnetic head is provided with a thin film recording head part and a reproduction element using the giant magneto-resistance effect or magnetic tunnel effect, and said apparatus performs magnetic recording and reproduction at an areal recording density of at least 30 Gb/in².

8. A magnetic recording apparatus comprising a magnetic recording medium, a magnetic recording medium drive unit which drives said magnetic recording medium, a magnetic head which performs recording and reproduction on said magnetic recording medium, a magnetic head drive unit which drives said magnetic head, and a recording/reproduction signal processing system which processes recording signals and reproduction signals sent to and from said magnetic head, wherein said magnetic recording medium comprises a soft magnetic backlayer provided on a non-magnetic substrate, a polycrystalline MgO film provided on said soft magnetic backlayer, a non-magnetic layer having a hexagonal close-packed structure provided on said polycrystalline MgO film and a perpendicular magnetic layer having a hexagonal close-packed structure provided on said non-magnetic layer, said magnetic head is provided with a thin film recording head part and a reproduction element using the giant magnetic resistance effect or magnetic tunnel effect, and said apparatus performs magnetic recording and reproduction at an areal recording density of at least 30 Gb/in².

9. A magnetic recording apparatus comprising a magnetic recording medium, a magnetic recording medium drive unit which drives said magnetic recording medium, a magnetic head which performs recording and reproduction on said magnetic recording medium, a magnetic head drive unit which drives said magnetic head, and a recording/reproduction signal processing system which processes recording signals and reproduction signals sent to and from said magnetic head, wherein said magnetic recording medium comprises a soft magnetic backlayer provided on a non-magnetic substrate, an non-magnetic layer comprising a material comprising Ti, Zr, Hf, Cr, Mo, Nb, V, W, Si, Ge, B, C or alloys having these elements as their main component, or oxides selected from the group consisting of SiO₂, Al₂O₃ or ZrO₂, provided on said soft magnetic backlayer, a polycrystalline MgO film provided on said non-magnetic layer, a non-magnetic layer having a hexagonal close-packed structure provided on said polycrystalline MgO film and a perpendicular magnetic layer having a hexagonal close-packed structure provided on said non-magnetic layer, said magnetic head is provided with a thin film recording head part and a reproduction element using the giant magnetic resistance effect or magnetic tunnel effect, and said apparatus performs magnetic recording and reproduction at an areal recording density of at least 30 Gb/in².