Methods for Measuring Piezoelectric, Elastic, and Dielectric Coefficients of Crystals and Ceramics

This paper considers methods for measuring the piezoelectric, dielectric, and elastic coefficients of crystals and ceramics and recommends certain preferred methods of measurement. Static measurements are not considered to be as satisfactory as dynamic measurements. Of the dynamic methods, measurements of the resonant and anti-resonant frequencies, the low frequency capacitance and the resistance at resonance appear to be the simplest and most accurate method, provided that the ratio of Q/r is high. Quasi-static methods are useful for crystals having a low ratio of Q/r, for determining the sign of the piezoelectric coefficients, and for production checks. Hydrostatic methods are useful for complicated crystals such as monoclinic types and for measuring a sum of two of the coefficients of electrostrictive ceramics. This measurement can be carried out for odd-shaped samples.