Browse Prior Art Database

Making Bias Layers on Amorphous Magnetic Bubble Devices

IP.com Disclosure Number: IPCOM000084165D
Original Publication Date: 1975-Sep-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+3]

Abstract

This technique provides amorphous magnetic bubble domain structures which require reduced magnetic bias fields for support of stable bubble domains. Total elimination of a bias field as provided by external structure is possible. A multilayered structure is shown in which an amorphous magnetic bias layer is used, together with an amorphous magnetic film for support of the bubbles.

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Making Bias Layers on Amorphous Magnetic Bubble Devices

This technique provides amorphous magnetic bubble domain structures which require reduced magnetic bias fields for support of stable bubble domains. Total elimination of a bias field as provided by external structure is possible. A multilayered structure is shown in which an amorphous magnetic bias layer is used, together with an amorphous magnetic film for support of the bubbles.

Amorphous magnetic films near the compensation point are used as the bias layers, while an amorphous magnetic film farther from the compensation point serves as the bubble domain film. This structure can be deposited in one vacuum pump-down in a sputtering system by holding the RF bias at one level for deposition of the bias layer, and by quickly changing the RF bias to another level to obtain the bubble film layer.

In an example of GdCoMo, the RF bias for the bubble domain film was 127V while the RF bias for the bias layer was 100V. The change in the bias level occurred in about one half to one minute. In this system, the target voltage was 800V.

An example of this structure was fabricated using a 0.7 micron thick, 2 micron strip width GdCoMo film which was exchange coupled to a thin GdCoMo layer with a compensation temperature slightly below room temperature. A stable bubble range from 12-47 Oe was obtained. This is a considerable reduction of bias field range from the typical bubble collapse fields of 150 0e for 2 micron amorpho...