Lattice Defects and the Self-Diffusion and Anomalous Specific Heat in Solidα−He3

Abstract

By using a simple model for lattice defects we have tested the hypothesis that the anomalous specific heat and the self-diffusion in solid $\ensuremath{\alpha}\ensuremath{-}{\mathrm{He}}^{3}$ are the result of the formation of lattice defects. It is found that vacancies and interstitials are present in about equal numbers and that their formation, probably in pairs, gives rise to the observed specific heat anomaly. It is contended that the motion of the vacancies gives rise to the self-diffusion.