Piezoelectric and Dielectric Properties of Calcium and Samarium Modified Lead Titanate Ceramics for Hydroacoustic Applications.

摘要

Piezoelectric lead titanate ceramics are promising materials for applications in underwater acoustics as well as ultrasound technology. These materials are highly anisotropic and possess high sensitivity to hydroacoustic signals applied under hydrostatic conditions. Ceramics of PbTiO3 doped with varying amounts of calcium and samarium were investigated. In addition, variations in firing and poling conditions were studied in the samarium-modified ceramics. Measurements of the hydrostatic piezoelectric properties were performed using an acoustic reciprocity technique. Results indicate that the piezoelectric sensitivity changes little with the addition of samarium after a certain concentration is reached, whereas the dielectric constant can be substantially varied over the range of substitution that was investigated. In contrast, the addition of calcium into lead titanate produces a minimum in the dielectric constant for 15% calcium substitution and causes voltage sensitivity of the material to reach a maximum for compositions with about 20% calcium.