Diffusion of silver in nanocrystalline copper between 303 and 373 K

Abstract

The diffusion of silver in nanocrystalline copper was measured at various temperatures between 303 and 373 K. The specimens used were disc shaped pellets of nanocrystalline copper (average crystal size 8 nm). The silver was diffused in from one of the flat surfaces. The resulting silver concentration profile was determined by electron beam microanalysis on taper sectioned specimens. The values of the silver diffusion coefficients range from 0.3 · 10⁻¹⁸m²/s at 303 K to 12 · 10⁻¹⁸m²/sat 373 K. The activation enthalpies deduced were 0.63 eV (for T > 353 K) and 0.39 eV (for T < 343 K).