INTERACTION BETWEEN ALKALI-METAL IONS M+ IN THE DEACTIVATION PROCESS OF QUARTZ-EMBEDDED AL-M+ CENTERS

The influence of the long- and short-range interactions between alkali-metal-ion compensators on the deactivation mechanism of Al-M+ centers (M = Li or Na) in quartz crystal during electrodiffusion is determined on the basis of a perturbation treatment of the Smoluchowski diffusion equation. Application to the deactivation rate of Al-Li+ in the presence of another Li+ ion shows that the asymmetry induced in the frequency jump of the first ion by the Coulombic interaction with the second appears to be a localized effect. When the second ion lies in adjacent wells of the Al-Li+ center, as expected in the model of diffusion and compensation, it is shown that the first-ion diffusion can be enhanced by two orders of magnitude with respect to the single-ion diffusion model without compensation.