State-dependent pyroelectric and thermal expansion coefficients in a PZT rectangular parallelepiped after compressive loading and unloading

A poled lead titanate zirconate rectangular parallelepiped was subject to compressive stress loading and unloading. After reaching a specific polarization, stress is removed and temperature is increased. Longitudinal polarization and longitudinal and transverse strains are measured during the temperature rise. A false contribution of leakage current to measured polarization is removed. From measured polarization and strains, pyroelectric and thermal expansion coefficients are evaluated. Dependence of the two thermal properties on remnant state variables is investigated. The evolution of remnant strains with relative remnant polarization is also discussed and compared with a previous work.