Effect of Phosphorus Content of the Magnetic and Electric Properties of Electroless Ni–P Film after Heat Treatment

Abstract

The magnetic and electric properties of electroless Ni–P films after heat treatment are investigated as a function of the P content in the deposit. The residual Ni, which means the surplus Ni (crystallized Ni) after Ni 3 P formation, is confirmed to determine the film properties of resistivity and saturation magnetization. Moreover, they depend only on the P content and are independent of the preparation conditions. The saturation magnetization, M s , and the reciprocal of resistivity, ρ -1 , are proportional to the amount of the residual Ni after sufficient heat treatment. An equation, showing the correlation between the P content and the resistivity or magnetization of the deposit after sufficient heat treatment, is proposed on the basis of the characters of ferromagnetic and metallic conductivity of the residual Ni matrix.