Electroless Ni–Co–B ternary alloy deposits: preparation and characteristics

Abstract

The formation of electroless Ni–Co–B ternary alloy deposits was studied using varying bath parameters and operating conditions. Variation in metallic ratio of the bath enables the formation of electroless Ni–Co–B deposits with varying contents of nickel, cobalt and boron. The Ni–Co–B deposits were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM) to assess the phase constituents, phase transition behaviour, thermal behaviour, Curie transition and magnetic properties, respectively. The study reveals that electroless Ni–Co–B alloy deposits are amorphous in the as-deposited condition. DSC traces indicate two exothermic peaks, corresponding to the separation of nickel phase from the amorphous matrix and formation of Co3B phase. TGA studies exhibit Curie transition peaks corresponding to nickel and Co3B. VSM studies show that the saturation magnetic moment increases with increase in the cobalt content of the film and with increase in annealing temperature.