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 degrees 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 degrees C).