SOLID-STATE AMORPHIZING TRANSFORMATIONS - THERMODYNAMICS AND KINETICS

Amorphous metallic alloys are thermodynamically metastable with respec t to one or more crystalline phases. Forming an amorphous alloy by an isothermal solid-state transformation requires starting from a state o f free energy higher than that of the amorphous phase and choosing a r eaction path that prevents the system from reaching the crystalline st ate of lowest free energy. Much has been learned about solid-state amo rphizing transformations from interdiffusion experiments in transition -metal thin-film multilayers. We review some of these experiments and discuss recent advances in our understanding of the thermodynamics and kinetics of the phenomenon.