Electromechanical behavior of single crystals of barium titanate

Mason(1) and Caspari and Merz(2) have made measurements of the electromechanical properties of barium titanate. Working with polycrystalline ceramics Mason(1) observed only a second order electro-strictive effect, since the first order piezoelectric effect was annulled because of the random orientation of crystal axes. Caspari and Merz(2) made static and dynamic electromechanical measurements on single domain crystals. However, their dynamic measurements were performed on small irregularly shaped crystals, which did not allow them to observe fundamental modes of vibration, and an absolute determination of the physical constants was impossible.