STUDY OF THE DIFFUSION OF NI INTO AMORPHOUS NI50ZR50 AND THE RESULTING STRAIN FORMATION

A set of multilayers of Ni/amorphous Ni50Zr50 Of various periodicities was deposited using de planar magnetron sputtering. The diffusion of Ni into the amorphous phase and the strain build-up in the Ni layers w ere measured in situ from the reduction and shift in Bragg peak intens ity and angle respectively. For short periodicities, a lowered interdi ffusivity was observed in agreement with other earlier experimental ob servations and theoretical predictions of stress effects in some amorp hous multilayers with a high viscosity. Furthermore, direct evidence o f stress formation owing to an unbalanced diffusional flow of the two species in Ni-Zr was obtained. These findings give further support for Stephenson's theory for lowered interdiffusion due to restricted stre ss relaxation in amorphous alloys.