Self-Diffusion in Solid Sodium. I

Measurements are reported for the self-diffusion of solid sodium over the temperature range, 0°—95°C. The data fit the empirical equation D=.242 exp(−10,450/RT) with an uncertainty of ±300 cal mole−1 in the heat of activation. The entropy of activation calculated from the temperature coefficient of the elastic modulus is in agreement with the value based upon the vacancy mechanism.