A set of multi-layers with various periodicities, that consisted of Ni plus amorphous samples of Zr50Ni50, was prepared by using direct-current planar magnetron sputtering. The diffusion of Ni into the amorphous phase, and strain build-up in the Ni layers, were deduced from reductions and shifts in the Bragg peak intensity and angle, respectively. In the case of short periodicities, a decreased interdiffusivity was observed; in agreement with previous experimental observations and with theoretical predictions of stress effects in amorphous multi-layers with a high viscosity. Direct evidence of stress formation due to an unbalanced diffusional flow of the 2 species in Ni-Zr was also obtained. It was concluded that these observations further supported the Stephenson theory of decreased interdiffusion, due to restricted stress relaxation, in amorphous alloys.

N.Karpe, J.Bøttiger, J.P.Krog, J.S.Conyers, A.L.Greer, R.E.Somekh: Philosophical Magazine A, 1997, 75[2], 461-8