Browse Prior Art Database

Bubble State Changer

IP.com Disclosure Number: IPCOM000083285D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Malozemoff, AP: AUTHOR

Abstract

A technique for converting magnetic bubble domains containing vertical Bloch lines into bubble domains having no vertical Bloch lines is provided.

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Bubble State Changer

A technique for converting magnetic bubble domains containing vertical Bloch lines into bubble domains having no vertical Bloch lines is provided.

In a magnetic bubble domain lattice file which is coded in terms of bubble domains having pure chiralities rather than those having vertical Bloch line structures, this technique has particular utility, since it may be desirable to change a bubble with two such Bloch lines into a bubble with no vertical Bloch lines.

The technique may be utilized with materials which have a nonlinear mobility region, such as a garnet film having a thickness of approximately 5.25 microns and a composition of (Tb(0.04)Eu(0.66)Y(2.3) (Ga(1.15)Fe(3.85))O(12), which exhibits a magnetization of 180 oersteds and a uniaxial anisotropy of 3250 erg/cm/3/. This material has a velocity versus drive characteristic as shown in Fig. 1.

Basically, the technique is to provide a pulse bias field to the material of such a polarity as to shrink the bubble; be short enough not to collapse the bubble; and have a field strength large enough to carry the wall velocity into the saturated nonlinear region. In this case, the pulse field would be greater than 20 oersteds. The probability of changing the bubbles in this material is such that for 100 pulses, approximately 95% of the bubbles will change.

To ensure 100% operation, a procedure as illustrated in Fig. 2 may be employed. Here, bubbles are tested to see if their state has changed. Thos...