ELECTRODEPOSITION OF NI-P AMORPHOUS-ALLOYS - OBSERVATIONS SUPPORTING THE INDIRECT MECHANISM OF PHOSPHORUS INCORPORATION

The mechanism for codeposition of nickel and phosphorus in electrodeposited Ni-P amorphous allows has not been clearly established. This paper presents experimental observations supporting the "indirect mechanism" for Ni-P alloy formation by electrodeposition from a phosphorous acid-based bath. Specifically, the indirect mechanism proposes that phosphine, PH3, is an intermediate in Ni-P electrodeposition. The experiments described here are; (i) reaction of nickel in aqueous solution with gaseous phosphine, (ii) electrodeposition from a nickel phosphite bath, and (iii) titration studies.