Diffusion of Thallous Chloride in Single Crystals of KCl by a Novel Spectrophotometric Method

摘要

A novel attachment to the Beckman DU spectrophotometer is described, by means of which the diffusion profile of some heavyhyphen;metal ions in alkali halides may be recorded.The diffusion of Tl+ions in KCl in the temperature range 270deg;hyphen;400deg;C was measured. It is concluded that the activation energy for the diffusion of Tl+varies with temperature, parallel to that of the selfhyphen;diffusion of K+ions, calculated from conductivity measurements. The diffusion constants of the Tl+, at any temperature, are several orders higher, as the associated vacancies of the divalent impurities present are also involved in the diffusion process.