DIFFUSIONAL ASPECTS OF THE SOLID-STATE AMORPHIZATION REACTION

Diffusional aspects of the solid state amorphization reaction (SSAR), specifically in early transition metal-late transition metal (ETM-LTM) systems, are considered. Self- and tracer diffusivities of ETM and LTM components in crystalline and amorphous phases are reviewed. The alloy characteristics leading to fast diffusion of LTM species and to good glass-forming ability are described. The nucleation of the amorphous phase in the SSAR is analysed, drawing parallels with interstitial-substitutional diffusion in semiconductors. Interdiffusion in amorphous ETM-LTM phases is considered in detail, taking into account stress effects, structural relaxation and the mixing thermodynamics of the amorphous phase.