Anion grain−boundary diffusion in soidum chloride

Abstract
The grain−boundary diffusion of 131I in Harshaw pure and Ca−doped NaCl was investigated in the temperature range between 430 and 560 °C. The Arrhenius plot of the grain−boundary diffusivity parameter Dδ displays a marked dip at around 510 °C. It is proposed that this dip is due to a phase transformation occurring at the grain boundary, possibly calcium segregation.