Studies of amorphous Ni-P thin films produced by the chemical reduction method

The paper is focused on the crystallization of Ni-P amorphous thin films produced by a chemical reduction method. The results of differential scanning calorimetric (DSC) experiments, Xray diffraction analysis (XRD), scanning (SEM) and transmission electron microscopy (TEM) studies of the microstructures are presented. The surface morphology of Ni-P amorphous films can be described in terms of arrays of spherical particles and holes, related to H-2, distributed mostly at their borders. The DSC studies of the films showed two exothermic effects at 370 and 440degreesC. This implies that crystallization proceeds in two stages. First, the metastable crystalline phase Ni12P5 is formed and then transforms into the equilibrium phases Ni3P and Ni. After annealing at a temperature below the peak of crystallization, the amorphous structure is visible. However, near the edge of perforations of TEM thin foils, the presence of the nanocrystals were revealed and the holes disappeared. Further research of both phenomena, nanocrystallization and healing of holes, are in progress.