Self-diffusion in naphthalene single crystals

Abstract

Abstract Studies of self-diffusion in pure single crystals of naphthalene have been carried out by a sectioning method, using a 14C labelled tracer. The effects of impurity content and pre-annealing upon the diffusion process “were examined. Diffusion coefficients are low compared to those found for other solid systems. In the best available crystals self-diffusion can be described by an equation D = 2·5×1015 exp (−(42·7×1·6 kcal mole−1) RT)cm2.sec−1. The self-diffusion process probably represents diffusion via a vacancy mechanism. Because of the low values of the diffusion coefficient, diffusion may be modulated by the presence of dislocations in the crystal lattice.