Electro-elastic moduli and frequency dependence of KN single crystal

Functional properties of KNbO₃ single crystal are characterized. Large polydomain plates cutted from an as-grown KNbO₃ crystal (oriented along [001]_c (45°-cut) direction) are used. At the fundamental resonance (10 MHz), thickness coupling factor is 65% and frequency dependence is measured with overtone resonances. Its variation is relatively high and reduces to around 45% at 160 MHz. Electro-elastic moduli are also determined by mixing measured parameters (from thickness and lateral modes) and constants already published as initial data. Final constants are obtained by a minimization process to tend toward a self-consistent electro-elastic moduli which is an important condition for numerical modelling.