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Electrodeposition of NI-FE Films

IP.com Disclosure Number: IPCOM000098310D
Original Publication Date: 1960-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Bartelson, BI: AUTHOR [+2]

Abstract

This process for electrodeposition of iron nickel thin film produces a film suitable for magnetic memory devices.

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Electrodeposition of NI-FE Films

This process for electrodeposition of iron nickel thin film produces a film suitable for magnetic memory devices.

A substrate 200 A degrees to 500 A degrees in thickness is provided on a non magnetic base by vacuum sublimation of nickel and iron. The thin film deposited on it should be 2000 A degrees to 3500 A degrees thick. The composition should range from 75-82% nickel and 18-25% iron for the best ferromagnetic properties.

To obtain the desired composition the following values and ranges may be used in the electrolyte water solution: (1) 25-60 grams/liter of Ni/++/ as Nickel Sulfamate

(2) 1-3 grams/liter of Fe/++/ as Ferrous Ammonium Sulfate

(3) 25 grams/liter of Boric acid

(4) 1.0 grams/liter of Saccharin

(5) 0.4 grams/liter of Sodium lauryl sulfate

(6) Bath pH -- 2.7 to 3.0

(7) Bath temperature -- 25-30 degrees C

(8) Cathode Current density -- 4-8 amperes per square ft.

(9) Magnetic field applied to electrolyte 40-150 oersteds.

The use of nickel sulfamate to provide the nickel ions produces a film having low coercive force and excellent orientation. It also produces a low stress plating.

The ferrous ammonium sulfate, being a double salt, is less prone to atmospheric excitation and aids in creating a more ductile film; however, ferrous sulfate may be used. The boric acid acts as a buffer, the saccharin as a stress reliever, and the sodium lauryl sulfate as a wetting agent. Agitation of the bath during plating influences the fi...