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

Synthetic quartz crystals were grown on S- and ξ-bar seeds and characterized by X-ray topography. For comparison, synthetic quartz crystals grown on intermediary cutting between S- and ξ-planes (φ=24-42°) 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 ξ-bar and two in the S-bar. For convenience, these new growth regions were called ξ-regions. The texture of ξ-regions of ξ- 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 γ-ray irradiation. The impurity analysis by atomic absorption spectroscopy revealed high content of Al in the ξ-regions with a concentration of about 30 ppm. Furthermore, the growth velocities of ξ-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