Browse Prior Art Database

Stressed Overlays for Bubble Domain Devices

IP.com Disclosure Number: IPCOM000087850D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Klokholm, E: AUTHOR [+3]

Abstract

A highly stressed metallic overlay can be used for bubble domain devices. In many cases, a nonmagnetic metal, such as Cr, can be used as a spacer layer between the NiFe used for propagation and the underlying bubble material. In other applications, the NiFe can be highly stressed.

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Stressed Overlays for Bubble Domain Devices

A highly stressed metallic overlay can be used for bubble domain devices. In many cases, a nonmagnetic metal, such as Cr, can be used as a spacer layer between the NiFe used for propagation and the underlying bubble material. In other applications, the NiFe can be highly stressed.

Fig. 1A shows a contiguous disk bubble domain device B using highly stressed NiFe disks 10 for bubble propagation. As field H reorients, as illustrated, the bubble domains follow the path denoted by arrow 12 around the periphery of the disk 10.

In Fig. 1B, the disks 16 are separated from one another and are deposited over underlying nonmagnetic layers 18. Layer 18 can be fabricated by evaporation of a high-melting-point metal, such as Cr, Mo and Nb, of about 1000- 3000 angstroms. Evaporation of a 1000-angstrom thick metallic film at room temperature will provide a force per unit width of 10/5/dynes/cm at the boundary of the stressed overlay.

If highly stressed NiFe is used without the underlying metallic layer, the NiFe can be stressed by omitting stress relieving agents (e.g., saccharin) from the appropriate electroplating bath, and by plating at relatively high deposition rates.

In Fig. 2, a bubble domain lattice L is confined by a boundary 20 of highly stressed metal. Translation of the lattice is by conventionally used devices.

In Fig. 3, highly stressed metallic layers 22 are under conductors 24, which are used to move the lattice back an...