Non-linear mechanical, electrical and thermal phenomena in piezoelectric crystals

摘要

Mechanical, electrical and thermal phenomena occurring in piezoelectric crystals were examined by non-linear approximation. For this purpose, use was made of the thermodynamic function of state, which describes an anisotropic body. Considered was the Gibbs function. The calculations included strain tensor ε_(ij) = f(σ_(kl),E_n,T), induction vector D_m = f((σ_(kl),E_n,T) and entropy S = f(σ_(kl),E_n,T) as function of stress σ_(kl), field strength E_n and temperature difference T. The equations obtained apply to anisotropic piezoelectric bodies provided that the "forces" σ_(kl), E_n, T acting on the crystal are known.