Influences of the phosphorus content on physicochemical properties of nickel-phosphorus deposits

Dependence of physicochemical properties, including crystalline information, morphology, microhardness, paramagnetism, roughness factor and hydrogen evolution ability, for Ni-P deposits on the phosphorus content, varying from 0 to 28 at.%, were systematically examined in this work. In general, the microhardness was gradually increased with the P content but an obvious decrease was observed when the Ni-P deposit contained sulfur (S). Nickel-phosphorus deposits with the P content above 12 at.% showed an amorphous structure while the deposits containing 4-12 at.% of P exhibited a poor crystalline structure. Morphologies of these deposits were found to be a function of the P content. The ferromagnetism of Ni was gradually transformed into paramagnetism with the introduction of P into the Ni matrix. The rate of hydrogen evolution reached a maximum at the P content of 8 at.%. This deposit exhibited the maximal roughness factor (Ra) and the highest specific activity (i/Ra) of H-2 evolution. (C) 2002 Elsevier Science B.V. All rights reserved.