Study of S- and ξ-bar synthetic quartz by X-ray topography

Abstract

Synthetic quartz crystals were grown on S- and /spl xi/-bar seeds and characterized by X-ray topography. For comparison, synthetic quartz crystals grown on intermediary cutting between S- and /spl xi/-planes (/spl phi/=24-42/spl deg/) seeds were also investigated. As a result, several new growth regions usually not present in the Y-cut of Y- and Z-bars synthetic quartz crystals have been observed, in a number of four in the /spl xi/-bar and two in the S-bar. For convenience, these new growth regions were called /spl xi/-regions. The texture of /spl xi/-regions of /spl xi/- and S-bars synthetic quartz crystals are quite similar, with strong distortions in the crystal lattice structure due to a high segregation of impurities. This fact was also verified by the degree of darkness after a /spl gamma/-ray irradiation. The impurity analysis by atomic absorption spectroscopy revealed high content of Al in the /spl xi/-regions with a concentration of about 30 ppm. Furthermore, the growth velocities of /spl xi/-regions are higher in comparison with other regions. In the present research the occurrence of the new regions is directly related to the orientation of seed, which can induce an aggregation of high concentration of Al impurity.