Published online by Cambridge University Press: 25 February 2011
Reactions in solids occur at interfaces. Following interfacial reactions has been difficult due to the small fraction of material making up the interfaces. In this paper, variable-temperature grazing x-ray diffraction is used to probe interfacial reactions in modulated ultra-thin film layered composites. This technique permits the monitoring of solid-state reactions in their earliest stages. The initial evolution of titanium-silicon interfaces within a superlattice is discussed. Our data suggest that the classical approach of modeling diffusion via Fick's laws is insufficient to describe the initial interdiffusion or mixing reaction at an interface.