MAGNETIC DEVICES UTILIZING ION-IMPLANTED MAGNETIC MATERIALS

• US 3,792,452 A
• Filed: 06/10/1971
• Issued: 02/12/1974
• Est. Priority Date: 06/10/1971
• Status: Expired due to Term

• Current Assignee: James Clayton North, Lawrence John Jr. Varnerin, Melvyn Dixon, Raymond Wolfe, Robert Alan Moline
• Original Assignee: James Clayton North, Lawrence John Jr. Varnerin, Melvyn Dixon, Raymond Wolfe, Robert Alan Moline
• Inventors: Moline, Robert Alan, Wolfe, Raymond, Dixon, Melvyn, North, James Clayton, Varnerin, Lawrence John Jr.
• Primary Examiner(s): Moffit, James W.
• Application Number:
  US05/151,728
• Time in Patent Office: 978 Days
• Field of Search: 340/174,174TF 252/62.56,62.57
• US Class Current: 427/526
• CPC Class Codes: C04B 35/26 based on ferrites
• CPC Class Codes: G11C 19/08 using thin films in plane structure
• CPC Class Codes: H01F 10/20 Ferrites
• CPC Class Codes: H01F 10/24 Garnets in general H01F1/346; multilayers, e.g. superlattices H01F10/3209; applying magnetic garnet films to substrates by sputtering H01F41/186
• CPC Class Codes: H01F 41/186 for applying a magnetic garnet film magnetic garnet materials H01F1/346; magnetic garnet films H01F10/24

Abstract

Magnetic anisotropy in oxidic magnetic materials is altered by strain which is induced by local expansion of the lattice through ion implantation. This compressional strain in the instance of a material having positive magnetostriction may result in an enhanced magnetic easy direction normal to a major surface. Exemplary rare earth iron garnet materials have been so processed as to result in a thin surface region having appropriate magnetic properties for incorporation in '"'"''"'"''"'"''"'"'bubble'"'"''"'"''"'"''"'"' devices.

Claims

2. Process of claim 1 in which the said material evidences a net magnetostriction of approximately at least 1 X 10 6.

3. Process of claim 2 in which the energy spectrum is such as to result in inhomogeneous ionic absorption in the direction of penetration.

4. Process of claim 2 in which at least a portion of the said irradiation is in a direction corresponding with the channeling direction for the said material.

5. Device produced in accordance with the process of claim 2.

6. Process of claim 2 in which the ionic species is hydrogen.

7. ProcesS of claim 2 in which the sign of the said magnetostriction is positive.

8. Process of claim 7 in which the direction of the said positive magnetostriction is approximately orthogonal to the surface being bombarded.

9. Process of claim 2 in which the said material is essentially homogeneous.

10. Process of claim 9 in which the said material is a portion of a bulk-grown crystal.

11. Process of claim 2 in which the said material comprises a layer on a supporting substrate.

12. Process of claim 11 in which the said layer is crystallographically epitaxial with respect to the said substrate.

13. Process of claim 12 in which the said layer is produced by liquid-phase epitaxy.

14. Process of claim 12 in which the said layer is produced by chemical vapor deposition.

15. Process of claim 12 in which the said layer evidences unique magnetic anisotropy prior to treatment.

16. Process of claim 2 in which the irradiated surface of the said material is subjected to a variation in dosage.

17. Process of claim 16 in which the said variation results by use of masking.

18. Process of claim 16 where such variation results primarily by selective illumination utilizing a beam of cross-section small relative to the surface being irradiated.

19. Process of claim 16 in which the variation is such as to produce a pattern corresponding with a relatively low coercivity region in which domain wall movement is favored.

20. Process of claim 2 in which the said magnetic material is of an oxidic composition.

21. Process of claim 20 in which the said material is a ferrimagnetic material of the garnet structure.

22. Process of claim 20 in which the said material is a magnetic ferrite of the spinel structure.