High-temperature stress-dependent piezoelectric and dielectric coefficient of soft Pb(Zr,Ti)O₃

The dielectric constant and the direct piezoelectric coefficient as well as the macroscopic ferroelastic behavior of co-doped Pb(Zr,Ti)O₃ were characterized from 25 to 350 °C as a function of uniaxial compressive stress. Experimental results show a decrease in the small signal piezoelectric coefficient and the permittivity with stress, although there exists a uniaxial compressive stress that significantly reduces the variation of the piezoelectric coefficient with increasing temperature, making it a possible method for sensors that operate over a large temperature range. In the vicinity of the depolarization temperature, the piezoelectric response rapidly decreases. This temperature, however, was observed well below the temperature at maximum permittivity. Experimental results reveal that uniaxial compressive stress shifts the temperature at maximum permittivity, giving insight into the effect of stress on the phase transition behavior in Pb(Zr,Ti)O₃, but does not apparently influence the depolarization temperature.