Chemical-reaction and diffusion rates in solids produced by shock compression

Explosive-driven hemispherical-implosions were used to create high dynamic pressures (up to 13 GPa) and temperatures (up to 450 K) in an exploratory investigation of chemical reactions and diffusion processes in different materials subjected to extreme conditions. Diffusion coefficients as high as 200 cm2/s and chemical reaction rates as fast as 1000 mol/s (in a volume of 0.2 cm3) were inferred from shock experiments with carbontetrabromide (CBr4) and copper (Cu) powder mixtures. An outdiffusion of Ga from a single crystal GaAs substrate into a polycrystalline indium thin film deposited on it was also observed and confirmed by scanning electron microscopy and energy dispersive x-ray microanalysis.