Formation of mixed crystals in equimolar KCl - KBr powder mixtures

The formation of mixed crystals in equimolar KCl-KBr powder mixtures is studied at temperatures from 406 to 602°C. The progress of the homogenization is followed by measuring the change in specimen capacitance as a function of time. The results indicate that the following three processes are involved in the mixed crystal formation: (i) grain boundary diffusion, (ii) volume diffusion of Cl⁻ ions, and (iii) volume diffusion of Br⁻ ions. The experimental results for the activation energies associated with these processes are respectively 1·5±0·2 eV, 1·9±0·2 eV and 2·1±0·1 eV.