Browse Prior Art Database

Control of Magnetic Properties of Cobalt and Cobalt Nickel Electrodeposits by Ratio of Hypophosphite and Ferrous Ion

IP.com Disclosure Number: IPCOM000095629D
Original Publication Date: 1964-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Judge, JS: AUTHOR

Abstract

The control of the magnetic properties of electrodeposits from cobalt or cobalt-nickel electroplating baths of the type containing hypophosphite ion is achieved over a wide range by the addition of small amounts of ferrous ion to the electroplating bath.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 60% of the total text.

Page 1 of 2

Control of Magnetic Properties of Cobalt and Cobalt Nickel Electrodeposits by Ratio of Hypophosphite and Ferrous Ion

The control of the magnetic properties of electrodeposits from cobalt or cobalt-nickel electroplating baths of the type containing hypophosphite ion is achieved over a wide range by the addition of small amounts of ferrous ion to the electroplating bath.

The left-hand drawing indicates the effect upon the coercivity of the resulting electrodeposit from the addition of small amounts of ferrous ion to a cobalt electroplating bath. The following bath composition and operating conditions are used: Cobalt Sulfate CoSO(4)x7H(2)O 60 gm/l. Ammonium Chloride NH(4)Cl 70 gm/l. Sodium Hypophosphite NaH(2)PO(2)xH(2)O 20 gm/l. Ferrous Sulfate FeSO(4) 0 to
30.0 gm/l. pH 3.0 Temperature 50 degrees C. Current Density 22 ma/cm/2/ Plating Time 15 seconds Substrate polished brass.

The coercivity of the electrodeposit is controlled in the range of about 100 oersteds to 700 oersteds for a cobalt electrodeposit, depending upon the amount of ferrous ion added while maintaining the hypophosphite ion content in the bath constant.

The concentration in the bath of the hypophosphite ion also affects the coercivity of the electrodeposit. The relationship is such that if the concentration of hypophosphite ion is increased, the coercivity of the deposit is increased. The right-hand drawing shows the lines of constant coercivity for a constant remanent magnetic moment of 8.3 x 10/...