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Beam Operated Memory Element

IP.com Disclosure Number: IPCOM000093391D
Original Publication Date: 1967-Sep-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Thompson, DA: AUTHOR

Abstract

This magnetic film memory element requires no wiring in the film plane in that reading and writing operations are accomplished by optical beams.

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Beam Operated Memory Element

This magnetic film memory element requires no wiring in the film plane in that reading and writing operations are accomplished by optical beams.

The basic memory element in A includes a magnetic storage film 1 which is positioned in the opposing stray fields f2 and f3 of two biasing magnets 2 and 3. At least one of such magnets is a temperature sensitive multilayered magnetic film device whose net stray field is controlled by selectively varying the temperature of the memory element. Laser beam source 4, or any other suitable heating device, is situated above magnet 2 or below magnet 3. The multilayer biasing element, either magnet 2 or 3, can involve either magnetostatic, i.e., anti- parallel, coupling or exchange, i.e., parallel, coupling.

The respective Curie temperatures of magnetic layers forming the biasing element differ sufficiently so that a substantial change in net stray field of the layers occurs whenever the ambient temperature crosses the lowermost of the respective Curie temperature levels. When the latter occurs, the net stray field f3, assuming the biasing element to be magnet 3, combines with the opposing stray field f2 of the other biasing element 2 to determine the resultant magnetization of the storage film.

In B is shown the construction of a biasing magnet 2 or 3. Layer t is a magnetic material with a high coercive force, such as a uniformly magnetized permanent magnetic layer. Layer b is a magnetic material hav...