Pressure Dependence of the Elastic Constants of Single Crystalline Aluminum Oxide

Abstract

Abstract The six single crystal elastic constants of aluminum oxide have been measured by the ultrasonic pulse superposition method at 25 °C as a function of hydrostatic pressure up to 10 kbar. A linear pressure dependence has been found in all cases. The results are compared and found to agree approximately with theoretical data for the hexagonal close‐packed structure with nearest neighbor central forces. They are also used to calculate the pressure dependence of the lattice parameters from Thurston's equation of state. The agreement with directly measured experimental data of Hart and Drickamer is excellent for one, and poor for the other lattice parameter.