Elastic Constants of Bismuth

Abstract

The six adiabatic elastic stiffness constants of bismuth have been determined at 301°K by an ultrasonic pulse echo technique. The results are: c₁₁ = 63.5, c₃₃ = 38.1, c₄₄ = 11.30, c₆₆ = 19.4, c₁₄ = +7.23, and c₁₃ = 24.5, all in units of 10¹⁰ d/cm². These values were redundantly determined by the measurement of 14 different velocities in four different single crystals of zone‐purified bismuth. The velocities are believed accurate to better than 1%, the principal error arising from the uncertainty of the transducer transit time correction. The moduli are in poor agreement with the previously determined static elastic compliance constants reported by Bridgman. Some data on the velocity of sound in bismuth at 98° and at 4.2°K are also presented.