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High Coercivity Magnetic Material

IP.com Disclosure Number: IPCOM000092463D
Original Publication Date: 1966-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Judge, JS: AUTHOR [+3]

Abstract

A magnetic film of extremely high coercivity is produced by chemical reduction onto an activated surface from a solution having the following composition: CoSO(4) . 7H(2)O - 31.5 g/1 NiSO(4) . 6H(2)O - 3.3 g/1 (NH(4))(2)HC(6)H(5)O(7) - 22 g/1 (NH(4))(2)SO(4) - 66 g/1 NaH(2)PO(2) - H(2)O - 20 g/1 pH=8.05+/-0.05 Temperature = 80 +/- 1 degrees C.

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High Coercivity Magnetic Material

A magnetic film of extremely high coercivity is produced by chemical reduction onto an activated surface from a solution having the following composition: CoSO(4) . 7H(2)O - 31.5 g/1 NiSO(4) . 6H(2)O - 3.3 g/1 (NH(4))(2)HC(6)H(5)O(7) - 22 g/1 (NH(4))(2)SO(4) - 66 g/1 NaH(2)PO(2) - H(2)O - 20 g/1 pH=8.05+/-0.05 Temperature = 80 +/- 1 degrees C.

The resulting film has a coercivity on the order of 1200 to 2500 oersteds. The coercivity is related to the thickness of the film.

The composition of the resulting films is on the order of 82.7% Co, 14.6% Ni, and 2.7% P. Their extremely high coercivity can be due to the crystallite size being on the order of the thickness of the films produced and to the favorable orientation of the apparently hexagonal crystals. There is a favorably high ratio of citrate ion to metal ion in the plating bath, on the order of 1.2:1. This allows for a high rate of deposition and encourages the desirable crystalline structure.

Other films, having useful magnetic properties, are obtained by varying the ratio of metal ions from the above bath, while the ratio of the cobalt ions to the nickel ions is maintained in the range of from 1:1 to 9:1.

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