The hydrothermal growth of α-quartz and the nature of the physico-chemical defects detected in the resulting crystal

Abstract

The development of α-quartz for high frequencies devices leads to a strong reduction of the thickness of the piezoelectric sheet. Such a thickness is comparable to the size of the defects. Consequently, the main objective for the improvement of the performances of α-quartz used as a piezoelectric material is to reduce the density of physico-chemical defects.

Our work has been focussed in two directions:

(i) the identification of different physico-chemical defects using the overlap of different techniques (X-ray topography, IR spectroscopy, Cathodoluminescence, Thermo-luminescence, EPR,…)

(ii) attempts at improving the correlations between the different parameters governing the hydrothermal crystal growth of a-quartz and the nature or the density of defects.

Key Words:

• Hydrothermal crystal-growth
• α-quartz
• density of defects