THE MORPHOLOGICAL STABILITY OF LATERAL GROWTH IN SOLID-SOLID PHASE-TRANSFORMATION DURING THIN-FILM INTERDIFFUSION IN AL CU BIMETAL FILMS/

This article describes the phenomenon of morphological instability in solid-solid phase transformations during thin-film interdiffusion, spe cifically related to the initial stages of precipitation when phase gr owth occurs along the interface between thin films. The experimental o bservations that revealed this effect will be presented, and a working hypothesis will be discussed. Experimental observations suggest that the ledge mechanism of growth is present in this system but does not i nhibit the formation of interfacial instabilities. It is proposed that morphological stability for solid-phase growth occurring during thin- film interdiffusion can be treated by the inclusion of a solute-source term into the two-dimensional perturbation approach generally used to study unstable growth morphologies. Experimental observations that pr ovide qualitative and semiquantitative support for the solute-source m odel are also presented.