公开(公告)号：US3738818A

公开(公告)日：1973-06-12

申请号：US3738818D

申请日：1971-06-03

Applicant: CONTROL DATA CORP

Inventor： STONE E ,  PATEL P

IPC: C09D5/23 ,  G11B5/64 ,  G11B5/73 ,  H01F10/06 ,  B32B15/00

CPC classification number: G11B5/7325 ,  G11B5/656 ,  H01F10/06 ,  Y10S428/90 ,  Y10S428/926 ,  Y10S428/928 ,  Y10S428/936 ,  Y10T428/12243 ,  Y10T428/12736 ,  Y10T428/12792 ,  Y10T428/12861 ,  Y10T428/12889 ,  Y10T428/12986

Abstract: A MAAGNETIC RECORDING MEDIUM AND A METHOD OF PRODUCING IT WHICH PERMITS THE PRODUCTION OF A MAGNETIC RECORDING MEDIUM HAVING A HIGH INTRINSIC COERCIVITY GREATER THAN 300 OERSTEDS AND AN 0.95 SQUARE B-H HYSTERESIS LOOP PERMITTING HIGH SWITCHING SPEEDS AND HIGH DENSITY RECORDING. THE MAGNETIC RECORDING MEDIUM COMPRISES AN ALUMINUM ALLOY DISC SUBSTRATE COVERED BY XINC AND NICKEL LAYERS, OVERLAID BY A GOLD FILM AND THIN-FILM COBALT MAGNETIC LAYER. THE FABRICATION PROCESS INVOLVES ELECTROLESS DEPOSITION OF THIN-FILM LAYERS OF ZINC AND NICKEL ON THE SUBSTRATE, THEN THE DEPOSITION OF A ONE-HALF MICRO-INCH GOLD LAYER CONVERTED BY A COBBALT PHOSPHORUS THIN-FILM LAYER. THE METHOD PROVIDES FOR TAILORING OF THE VALUE OF COERCIVITY INDEPENDENT OF THE THICKNESS OF THE MAGNNETIC FILM LAYER.

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