Aqueous DC Electrodeposition and Mechanism of Magnetic SmCo Alloys

Abstract

Electrodeposition of Sm-Co magnetic alloys have previously been investigated using Hull cells, DC and pulse methods from aqueous media. The basic electrodeposition solution had been selected as lM samarium sulfamate, 0.05M cobalt sulfate and 0.15M glycine. Solution temperatures ranged from 25oC to 60oC. Increased current density (CD) and temperatures increase deposit Sm content of metallic SmCo alloys. Deposit Sm contents were obtained, with appropriate heat treatment, to produce the intermetallics: SmCo3 (25.0 at %), Sm2Co7, (22.2 at %), SmCo5 (16.7 at %) and Sm2Co17 (10.5 at %). The present work investigates the DC electrodeposition of SmCo alloys in varying aqueous solution constituents, their composition and operating conditions and to consider the coordination chemistry of SmCo ions and aminocarboxylates (glycine). The hydrogen atoms generated at the cathode surface provide the electrons for the sequence of stepwise reduction of Sm and Co in the polymeric glycine complexes to deposit SmCo alloys.