An impedance spectroscopic study was made of the effect of lengthy annealing, at temperatures ranging from 900 to 1700K, upon the alternating-current conductivity of so-called hydrogen-swept quartz. Transient and irreversible effects were observed during annealing. In particular, a monotonic enhancement of the conductivity was detected at temperatures of between 900 and 1300K. At higher annealing temperatures, the opposite occurred. The experimental results were explained within the framework of a phenomenological model which involved 2 equilibrium reactions. Infra-red spectroscopic measurements revealed that an indirect role, in ionic transport dynamics, was played by H impurity.

P.Campone, M.Magliocco, G.Spinolo, A.Vedda: Radiation Effects and Defects in Solids, 1995, 137[1-4], 277-83