Ferroelectric, piezoelectric and pyroelectric properties of Sr1+xBi4-xTi4-xTaxO15 ceramics (x=0-1)

The dielectric, ferroelectric, piezoelectric and pyroelectric properties of bismuth layer-structured ferroelectric (BLSF) Sr1+xBi4-xTi4-xTaxO15 (x = 0-1) ceramics were investigated. The Curie temperature of this system is from 540degreesC to 30degreesC, and all samples show ferroelectricity at room temperature. From piezoelectric measurements, Sr1.1Bi3.9Ti3.9Ta0.1O15 was found to have the largest piezoelectric coefficient and electromechanical coupling factor of compounds in this system. The thermally stimulated current measurements showed that Sr1.1Bi3.9Ti3.9Ta0.1O15 also has excellent pyroelectric responses, and the enhancement of pyroelectric properties may partially result from a relatively large temperature-dependent internal electric field which was observed from the polarization-electric field (P-E) hysteresis loops.