THE PRESSURE EFFECT ON AU DIFFUSION IN AMORPHOUS PD40NI40P20

The activation volume for diffusion of ion-implanted Au in the amorphous metal Pd40Ni40P20 has been determined from the pressure dependence of the diffusivity. Samples, in the well-relaxed state at 563 K prior to implantation, were annealed at 563.0 K for 12 h at pressures from 0 to 0.75 GPa. Au concentration profiles before and after annealing were determined by Rutherford-backscattering spectrometry (RBS). A gaussian concentration profile was adjusted to fit the RB spectrum of Au, and from the change in the width of the gaussian for samples annealed at various pressures. the diffusion coefficients and an activation volume ((11 +/- 4) x 10(-3) nm3, i. e. close to the atomic volume of Au) were determined. The effects of surface contamination and surface crystallization on these results are considered and found to be negligible.