The growth of high acoustic Q quartz at high growth rates

Abstract

A technique for the hydrothermal growth of high acoustic Q (>106) quartz at rates above 100 mil/day (2.5 mm/day) is reported. This technique hinges upon the fact that the solid solubility in quartz of the proton which causes loss is decreased as the growth temperature increases. Typical conditions for high Q-high rate growth are: 374 °C, crystallization temperature; 23°, temperature difference (ΔT) between dissolving and growth zones; 88% fill; 40000 psi (2759 bar) and 103 mil/day growth rate on a surface within 5° of a basal (0001) plane. The Q is 1.4 × 106. The concept of effective distribution constant developed to describe impurity segregation in melt growth is shown to be applicable to solution growth with appropriate modifications. A new quantity, the effective equilibrium constant for the segregation of (M+3) ions and (H+) in quartz is shown at constant temperature to depend on rate (where rate changes are brought about by fill and ΔT changes) in a manner analogous to the dependence of the effective distribution constant in melt growth. It is suggested that the concept of effective equilibrium constant can be extended to polycomponent growth in general.