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Treatment of Recording Material

IP.com Disclosure Number: IPCOM000096524D
Original Publication Date: 1963-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Appel, FH: AUTHOR

Abstract

This method provides a technique for converting magnetic material to nonmagnetic or, alternatively, making nonmagnetic material magnetic. Such is through the application of heat to discrete portions of a magneto-thermally sensitive material. In one form, the technique is used to provide discrete record areas on a magnetic record such as the discrete tracks of magnetic oxide provided on a magnetic disc record.

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Treatment of Recording Material

This method provides a technique for converting magnetic material to nonmagnetic or, alternatively, making nonmagnetic material magnetic. Such is through the application of heat to discrete portions of a magneto-thermally sensitive material. In one form, the technique is used to provide discrete record areas on a magnetic record such as the discrete tracks of magnetic oxide provided on a magnetic disc record.

Under the application of a proper amount of heat, a magnetic oxide, such as gamma Fe(2)O(3), is made nonmagnetic, for instance converted to alpha Fe(2)O(3) by heating to about 500 degrees C in the absence of air, for example. During heating, the treated surface is flooded with some inert gas, such as nitrogen, to prevent oxidation of the plastic binder in the coating. Alternatively, nonmagnetic, heat-magnetizable material, such as Kanigen-plated nickel, is rendered magnetic under the application of heat to about 750 degrees F, for instance, for such nickel films.

This technique becomes especially useful when the source of heat is an attenuated heat-beam, such as a laser beam. It can heat very quickly and in a small localized area and, further, can be used to produce discrete magnetized areas, or tracks, on a magnetic record.

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