Magnetic-resistance device, and magnetic head employing such a device

• US 6,205,008 B1
• Filed: 05/16/1996
• Issued: 03/20/2001
• Est. Priority Date: 10/06/1993
• Status: Expired due to Fees

• Current Assignee: Sagem SA (Safran SA)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Kelly, Paul J., Gijs, Martinus A. M.
• Primary Examiner(s): Ometz, David L.
• Application Number:
  US08/649,909
• Time in Patent Office: 1,769 Days
• Field of Search: 360/113, 360/119, 360/324, 360/324.1, 360/324.11, 360/324.12, 360/324.2, 338/32.R, 324/207.21, 324/252, 365/157, 365/158
• US Class Current: 360/324
• 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: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• 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 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: H01F 10/3213 Exchange coupling of magnetic semiconductor multilayers, e.g. MnSe/ZnSe superlattices semiconductor materials for use in semiconductor devices H01L29/12
• CPC Class Codes: H01F 10/324 Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A magneto-resistance device comprising two layers of ferromagnetic material mutually separated by at least one interposed layer of non-ferromagnetic material, in which at least one of the layers of ferromagnetic material comprises half-metallic material, and preferably both ferromagnetic layers are principally comprised of half-metallic material.

Claims

1. A magneto-resistive device comprising two layers of ferromagnetic material mutually separated essentially only by at least one layer of a non-ferromagnetic material, characterized in that said at least one layer of non-ferromagnetic material is electrically insulating and is in contact with one of said layers of ferromagnetic material and at least one of the layers of ferromagnetic material comprises a half-metallic material.

2. A magneto-resistance device according to claim 1, characterised in that both ferromagnetic layers are principally comprised of half-metallic material.

3. A magneto-resistance device according to claim 2, characterised in that the half-metallic material is a metal oxide.

4. A magnetic head comprising a magneto-resistance device as claimed in claim 2.

5. A magneto-resistance device according to claim 1, characterised in that the half-metallic material is a metal oxide.

6. A magneto-resistance device according to claim 3, characterised in that the half-metallic material is selected from the group formed by Fe₃O₄, CrO₂, and mixtures thereof.

7. A magnetic head comprising a magneto-resistance device as claimed in claim 6.

8. A magnetic head comprising a magneto-resistance device as claimed in claim 5.

9. A magnetic head comprising a magneto-resistive device as claimed in claim 1.