Corrosion resistant magnetic recording media
AssigneeInternational Business Machines Corporation
InventorsJohn D. Michaelsen, Daniel A. Nepela, Peter B. P. Phipps
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Abstract
A thin film magnetic recording medium for deposition on a record carrier includes a ferromagnetic alloy containing iron, cobalt and chromium. The ferromagnetic alloy consists of from 0-55% cobalt, from 8-22% of chromium with the remainder iron. The preferred range of chromium is from 10-18%. The magnetic recording layer is vacuum deposited over an extended portion of a record carrier for storing information which is represented by the spatial distribution of magnetic transitions in the magnetic layer. The iron-cobalt-chromium or iron-chromium composition according to this invention, gives the best magnetic properties consistent with excellent corrosion resistance.
Claims6
A recording media for storing magnetic transitions representative of data information over an extended portion, said media comprising:
- a substrate;
- an undercoat layer deposited on said substrate;
- a thin film layer of ferromagnetic material deposited on said undercoat layer, said ferromagnetic material consisting essentially of, in weight percentage from 0-55% cobalt, from 8-22% chromium, with the remainder being mainly iron;
- said thin film having a remanent magnetization product of remanence M.sub.r times the thickness of said layer (t) greater than 1.times.10.sup.-3 emu/cm.sup.2 ;
- said layer having a thickness between 300 and 600 angstroms;
- said layer having a coercivity H.sub.c between 300 and 800 oersteds;
- and
- an overcoat protective layer deposited over said ferromagnetic material thin film layer.
Dependencies are inferred from the claim text.