Nonlinear piezoelectric effect in ferroelectric ceramics

Ferroelectric ceramic is often subjected to both high electric and high stress in piezoelectric power devices, causing nonlinear piezoelectric response. In this work, nonlinear behavior of the ferroelectric ceramic, Pb(Mn1/3Sb2/3)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3, electrically excited at resonant mode was studied. It was found that an induced vibration stress has a greater effect on the nonlinearity than an electric field. Mechanical loss factor Q(m)(-1), Young's modulus c(E) and piezoelectric d(31) constant are shown to be a function of the square of the vibration stress above the stress threshold. It was also found that the nonlinear proportional constant for the stress becomes smaller in the order of Q(m)(-1), d(31) and c(E), and that the softer in piezoelectricity the material is, the larger the nonlinear proportional constant becomes.