Bismuth-modified BiScO3–PbTiO3 piezoelectric ceramics with high Curie temperature

New piezoelectric ceramics, 0.15BiScO3-0.85(Pb1 - 3x / 2Bix)(Ti0.98Mn0.02)O3 (x = 0.04~0.10), were prepared by using conventional solid phase processing. The results of X-ray diffraction (XRD) show that the ceramics have a single phase tetragonal perovskite structure. The ceramics, poled by normal poling process, have piezoelectric coefficient d33, planar electromechanical coupling factor kp and thickness electromechanical coupling factor kt of 50~60 pC/N, ~ 11% and ~ 30%, respectively. An extremely high mechanical quality factor Qm of 1540 was obtained at the composition x = 0.08. The Curie temperature (TC) is in the range of 520-550 deg C, higher than 490 deg C of pure PbTiO3. The combination of good piezoelectric properties and high TC makes these ceramics suitable for elevated temperature piezoelectric devices.