Materials for high temperature piezoelectric transducers

The most significant advance in this field in the past year has been the demonstration that single-crystal langasite, La3Ga5SiO14, can be used, at least at high frequencies, at temperatures up to 1000°C. New evidence suggests that domain-wall contributions to the piezoelectric response of bismuth-titanate-based high temperature ferroelectric ceramics may be controlled using suitably chosen dopants. Modified bismuth titanate compositions are interesting for sensor applications in the medium temperature range (up to 500°C).