Nonlinear, elastic, piezoelectric, electrostrictive, and dielectric constants of lithium niobate

All eight electrostrictive, all three third‐order dielectric, all thirteen third‐order piezoelectric, and all fourteen third‐order elastic constants of lithium niobate have been determined. Measurements for the electrostrictive constants have been made by measuring the electric capacity in selected directions when the directed static stresses were applied to the crystal. The third‐order dielectric constants have been calculated from these measured electrostrictive constants and the measured capacitance as functions of the applied static electric field. The third‐order piezoelectric and elastic constants have both been determined from the above‐mentioned two kinds of measured constants and the measured velocities for small‐amplitude ultrasonic waves as functions of several applied stresses and static electric fields.