Nonlinear constants of quartz thirty years after the first nonlinear elastic tensor

Thirty years have expired since the determination (in 1966) of the third-order elastic constants of /spl alpha/-quartz by Thurston, McSkimmin and Andreatch, Jr. As their calculation was made disregarding the piezoelectric character of quartz, the values of the constants are distorted. The distortions have propagated into the entire family of the existing values of the third-order electromechanical constants of quartz including electroelasticity, electrostriction and third-order permittivity. They have also afflicted a recent attempt to determine the third-order elastic constants which was intended to correct the original omission. Independently of these distortions, strong statistical evidence suggests a significant lack of agreement among the third-order constants obtained by independent methods. For these two reasons the available values of the third-order nonlinear constants of /spl alpha/-quartz-31 constants in total-are not the true material constants and should be recalculated. A meaningful attempt to do so could be based on the available experimental data which should be analyzed using a nonlinear theory applied to all data consistently and without substitutions.