Evaluation of piezoelectric properties of Bi₄Ti ₃O₁₂-based ceramics at high temperature

Nowadays many industries as aeronautic, aerospace, etc, are claiming for new sensors and actuators that can operate in hostile environments. PZT ceramics are the common materials used in piezoelectric devices, however their low Curie temperature prevents their use at high temperatures. Bi₄Ti ₃O₁₂-based ceramics show a great potential for high temperature applications. Although piezoelectric parameters of BIT ceramics are well described at room temperature, its behaviour at high temperatures is almost lacking. This paper describes an experimental set-up to measure the piezoelectric properties of high temperature piezoceramics up to 700°C. The variation of piezoelectric parameters of W-doped BIT ceramics as a function of temperature indicates that their operating temperature extends up to 500°C, surpassing the expected one (1/2Tc) in more than 200°C.