Gadolinium iron alloy for thermomagnetic recording - with high sensitivity for use with gallium arsenide laser

摘要

Carrier for thermo-magnetic recording has a substrate made of an electrically-insulating material, e.g. glass, coated with a working layer of iron-gadolinium strip with the direction of easy magnetisation perpendicular to the surface of the substrate. The strip contains 65 plus-or-minus 5 wt.% gadolinium, the remainder being iron. The gadolinium iron strip is pref. applied to the substrate by thermal evapn. in a vacuum of 10-6 torr. The working layer requires no coating and works for >=2 years at room temp.; only weak recording and erasing fields (ca 90 0) are required. The high sensitivity of the Gd-Fe permits the use of a GaAs semiconductor laser for data recording so that an economic magneto-optic memory store of high capacity is achievable using this carrier.