Abstract:
NONDESTRUCTIVE READ-OUT CHARACTERISTICS OF PERMALLOY FILM COATED WIRES FOR MAGNETIC MEMORIES ARE SIGNIFICANTLY ENHANCED BY SELECTIVELY DEPOSITING FINE GRAINED ISLANDS OF A FACE CENTERED CUBIC METAL, E.G., GOLD, ALONG THE NODULAR SURFACE OF A NONMAGNETIC SUBSTRATE OF PREFERABLY DISSIMILAR METAL, E.G., COPPER, PRIOR TO DEPOSITION OF THE PERMALLOY FILM THEREON.
Abstract:
A CIRCUMFERNTIAL MAGNETIC ORIENTATION IS OBTAINED IN A NICKEL-IRON MAGNETIC FILM DEPOSITED UPON A TUNGSTEN WIRE CORE SUCCESSIVELY PLATED WITH GOLD, COPPER AND GOLD LAYERS BY REVOLVING A LINEAR MAGNETIC FIELD GREATER THAN 15 OERSTEDS ABOUT THE WIRE SUBSTRATE DURING THE PLATING OF THE NICKEL-IRON FILM. THE FIELD IS ROTATED AT A SPEED GREATER THAN ABOUT ONE REVOLUTION PER 10 A. LAYER OF MAGNETIC FILM DEPOSITED AND, AFTER DEPOSITION OF THE MAGNETIC FILM TO A THICKNESS LESS THAN 15,000 A., THE MAGNETIC FILM PLATED WIRE IS ANNEALED AT A TEMPERATURE BELOW 400*C. TO DECREASE THE DISPERSION OF ANISOTROPY OF THE FILM IN THE CIRCUMFERENTIAL DIRECTION.
Abstract:
A rotating disc coated with a thin magnetic film is used in a vacuum system as a high density data storage medium. A group of magnetic recording heads, overlapped in stairstep fashion, are actuator-positioned so that one complete band of tracks may be recorded in a single revolution of the disc. Interrogation is accomplished by controllably deflecting an electron beam in a radial direction toward any predetermined track. The electron beam is reflected by an electric potential on the disc surface and deflected by the magnetic field just above the surface. Differential sensing of reflected current allows determination of the stored information.