Effect of high pressure on the crystallization of an amorphous Pd80Si20 alloy

Amorphous Pd₈₀Si₂₀ alloy was annealed at temperatures ranging from 200 to 400° C while being subjected to a pressure of 100 kbar. Structural changes taking place in the alloy during the annealing were investigated by X-ray diffraction after each pressurization experiment. Pressure has been shown not to enhance, but to retard the crystallization of the amorphous alloy on annealing. Crystalline phases which form under high pressure have, in contrast to those forming under atmospheric pressure, simpler structures; i.e. the phase appearing initially has a face-centred cubic structure and the other, appearing subsequently and having a higher silicon content, has a body-centered tetragonal structure.