Temperature dependence of strain-polarization coupling in ferroelectric ceramics

The temperature dependence of the strain, electric field, and polarization of lead zirconate titanate ceramic under unipolar electric fields up to 1.3 kV mm-1 from -50 °C up to +200 °C is reported. An electrostrictive model is shown to describe the response to high levels of induced polarization and electric field below and above the ferroelectric to paraelectric transition. This is despite nonlinearity and hysteresis in the strain-field response. A linear strain-polarization response is shown to be an approximation to a quadratic electrostriction which is invalid at higher temperatures while the electrostriction holds across the temperature range.