The Influence of Temperature and Electric Field on The Etch-Channel Density in Swept Cultured Quartz

It is known that sweeping can reduce the etch-channel density in quartz. Various electrode types may be used for sweeping quartz. Usually employed are platinum-foil electrodes under pressure or evaporated metallizations to the z-surfaces with pressure or welded contacts. The reduction in etchchannel density varies with the electrode type and with the temperature and applied field conditions. In the present work, emphasis was on studying sweeping with gold metallized z-surfaces. The temperature and field values which reduce etch-channel density to zero were investigated.* Under certain values of temperature and field, gold has been found to diffuse into the quartz. This diffusion correlates with the reduction of etch-channels to zero. Using dark-background light-scattering microscopy, it was found that etch-channels were originating at the surface intersection of straight growth tunnels as previously reported by Katz, et al. ,I and at irregularly curved defect lines (possibly precipitate decorated dislocations) which invariably connect the growth tunnels. After sweeping, metal decoration of both defect types was also observed using the light-scattering method.