The activation energies of the crystallization of amorphous Ni81 P19 alloy films

Abstract

In situ transmission electron microscopic observations were carried out to study the crystal growth kinetics of amorphous Ni81 P19 alloy films prepared by vacuum deposition. In the first stage of crystal growth a metastable Ni3P phase with hexagonal symmetry appeared. The growth rates were independent of time at a given annealing temperature. The activation energies along [1 0 0] and [1 1 0] directions were estimated to be 3.12 eV for the 55 nm thick and 3.22 eV for 20 nm thick film samples. Similar measurements for the stable and the metastable phases of thin foil samples were also carried out. The smaller activation energies for the foil samples than the film samples are explained by assuming that the compositional requirement at the crystalline-amorphous interface and the jumping of atoms to the crystal sites occur in series.