Crystallization behavior of amorphous Ni-P chain dendritic alloy particles prepared by pulse discharge

Ni-P alloy particles were synthesized by means of pulse discharge in nickel salt solution.The microstructure characterization and crystallization behavior of the particles were investigated using field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM),X-ray diffraction analysis (XRD) and differential thermal analysis (DTA).The results show that the particles exhibit the morphology of a dendrite-like and chain-like combination,with the diameter of up to about 500 nm and the length of several microns.Their structure is amorphous and maintains at temperatures lower than 280 ℃,but begins to crystallize into metastable phases Ni₅P₂ and Ni₁₂P₅ at 300 ℃.Ni and Ni₃P stable phases appear at 320 ℃,and the metastable phases disappear above 400 ℃.The crystallization activation energy is 291.76 kJ·mol^-1 determined by the Kissinger equation.