Hydrogen diffusion in fluorapatite

Abstract

Hydrogen diffusion experiments of fluorapatite under deuterium enriched water vapor conditions were performed to investigate the species, temperature dependence and anisotropy of hydrogen diffusion in apatite. Diffusion profiles show that diffusion species in apatite are H⁺ rather than OH^-. Diffusion coefficients obtained by this study are about one orders of magnitude smaller than that of Higashi et al. (2017) which are affected by defects in the apatite crystal. Anisotropy of hydrogen diffusion in apatite is small relative to oxygen and fluorine diffusion in apatite.