AMORPHOUS-ALLOYS FORMED BY SOLID-STATE REACTION

Many binary systems exhibit an amorphization reaction in the solid state. Closely related to this phenomenon is the formation of disordered interfaces in metal multilayers during vapor deposition. We have observed an amorphization reaction in the Gd/Co system in situ during sputter deposition by using grazing incidence X-ray scattering. We relate this observation to disordered interface development in other systems, and present a simple model for bulk diffusion limited growth of the disordered layer during deposition. From the large chemical interdiffusivity calculated from this model, we conclude that other effects, perhaps surface diffusion of Co to Gd grain boundaries, are responsible for the rapid amorphization of Gd by Co.