Elastic Constants of Thallium Single Crystals in the Temperature Range 4.2°–300°K

Abstract

The five independent elastic constants of single crystals of the hexagonal allotrope of thallium have been determined by the ultrasonic pulse‐echo technique over the temperature range, 4.2°–300°K. The values at 300°K in units of 10¹¹ dyn/cm² are C₁₁=4.080, C₃₃=5.280, C₄₄=0.726, C₁₂=3.54, and C₁₃=2.9. The compressibility derived from these elastic constants is in good agreement with the compressibility obtained by Bridgman from hydrostatic measurements on polycrystalline samples.