Evidence of Nickel Phosphide Ni[sub 2]P in As-plated Electroless Nickel

The dissolution rate of as‐plated electroless nickel containing between 3.2 and 12.5 w/o phosphorus is studied in hydrochloric acid. Two reaction rates can be distinguished: first the dissolution of the nickel phase (fast), second that of a phase containing 21 w/o phosphorus whose stoichiometry corresponds to the composition of the nickel phosphide (slow). The content of the as‐plated electroless nickel corresponds to the entirety of phosphorus bonded to nickel.