Magnetic Bubble Memory
Abstract
This report describes the progress made during the first year of this program and covers two major areas of investigation. The first one is a study of the temperature stress/anneal effects on the permalloy thin films that are used for the bubble propagation and detection elements. It has been found that the magnetic, electrical, and physical properties of the film vary significantly with temperature stress/anneal and deposition parameters. It is an objective of this study to optimize the film deposition parameters and to be able to predict the failure modes for bubble devices by providing knowledge of the magnetic behavior of the thin films to accelerated thermal stress. The second major area of investigation is the development of bias field temperature compensating techniques using temperature dependent magnets. A review of bubble memory package concepts and techniques is given which covers many packaging areas that are being studied by Rockwell International. A comparison of several thick and thin chevron bubble sensors is also made. Thin detectors have the highest sensitivity per bubble stretch; however, the detector current is limited by Joule heating. Of the thick types the full conductor shorted chevron was found to have the highest sensitivity. For two active bubble sensors in a bridge detecting 180 deg apart half conductor shorted chevron detectors are used which have slightly smaller sensitivities. Except for the detector comparison no device development was performed on this program. Also no effort was made to develop or improve bubble materials for device applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1974
- Accession Number
- ADB005778
Entities
People
- D. Heinz
- J. Ypma
- L. R. Tocci
- P. K. George
- R. Bailey