Decomposition of Equimolar NaBr-KBr Mixed Crystal

Abstract

Abstract The decomposition of equimolar NaBr-KBr mixed crystal has been studied within a temperature range of 115 to 251 °C. The measurements were made with an apparatus suitable for continuous recording of the changes in specimen capacitance. The results indicated that the decomposition takes place in three steps. A report is made on the decay constants, half-lives, and activation energies of the first two steps - the nucleation of a freshly prepared specimen, and the subsequent decomposition of the nucleated mixed crystal into components which are nearly pure. It was found that above 150 °C the rate of these processes is affected by a temperature-dependent effect of do-main formation. The experimental result for the activation energy associated with the processes, 0.84 ± 0.05 eV, compares favourably with the value derived from a simple diffusion model.