Reactive diffusion in multilayer metal/silicon nanostructures
National Technical University ‘Kharkiv Polytechnical Institute’, ul. Frunze 21, Kharkov, 61002, Ukraine
Reactive diffusion in nanomaterials differs widely from that in bulk materials. Reviewed in this paper are the basic models and experimental data on how diffusion and phase transformations occur in multilayer nanosystems as these are being prepared and subsequently thermally annealed. The growth kinetics of amorphous silicide phases in Sc/Si and Mo/Si multilayer periodic systems are studied using the combination of high-resolution transmission electron microscopy and small-angle X-ray diffraction. A model is proposed for silicon diffusion through amorphous silicide that undergoes structural relaxation and crystallization as it grows. Anisotropic diffusion and growth of the silicide phase at adjacent interfaces are studied, and the diffusion parameters are measured for the earliest stages of diffusion annealing.