Self-Diffusion and Radical Recombination in Imidazole Single Crystal

Self‐diffusion measurements in imidazole single crystal in the $a$ crystallographic direction were performed with either Cl4 or tritium bound to nitrogen as tracers. Radical recombination studies were also performed as an independent method of assessing diffusive motion in the crystal. From both of these studies, it is concluded that, in the temperature range 80–90°C, self‐diffusion and radical recombination occur by a vacancy‐controlled bulk diffusion process. There is no indication that cooperative transport of protons through the crystal, which dominates the conduction process in the $c$ direction, and appears as a component of the conduction process in the $a$ direction, is at all operative in the diffusion process.