| 摘要 |
1295063 Magnetic storage devices; magnetooptic storage devices GENERAL ELECTRIC CO 7 Nov 1969 [18 Nov 1968] 54627/69 Heading H3B [Also in Division C7] A magnetic film less than 1 mil. thick is made of an alloy containing 50-65 atomic per cent Rh, the balance, apart from impurities and incidental ingredients, being Fe (see Division C7) and has a first order transition between the ferromagnetic and anti-ferromagnetic states of over 50% of the film when thermally cycled through the hysteresis loop thereof. The film may be made by vapour deposition.with heattreatment in an O 2 containing atmosphere to obtain the required magnetic characteristics. Information is recorded by selectively heating regions of the film, of which the substrate (e.g. of Si or quartz) may be soldered to a thermoelectric base (e.g. of Bi, Pb, Sb, Ag-In or Cu- Ga tellurides), by laser or electron beam and then subjecting it to the action of a magnetic field. The information may be read out optically,by application of a solution of colloidal iron oxide, after application of a pulsed magnetic field over 300 oersteds to align.the ferromagnetic bit sites, alternatively, electron beam microscopy may be used. The erasure of the information may be accomplished by energizing the thermoelectric substrate or mechanically by application of strain (e.g. by rubbing with a cotton swab). |
