Dielectric and piezoelectric properties of (Bi 0.9 Li 0.10 )(Sc 0.90 Ta 0.10 )O 3 PbTiO 3 high‐temperature relaxor piezoelectric ceramics

(1 −  x )(Bi 0.90 Li 0.10 )(Sc 0.90 Ta 0.10 )O 3 x PbTiO 3 (BLSTPT x ; x  = 0.60–0.65) ceramics were prepared using the conventional mixed oxide method. X‐ray diffraction analysis revealed that BLSTPT x has a pure perovskite structure. In the vicinity of the morphotropic phase boundary, which was observed in the compositional range 0.61 ≤  x  ≤ 0.62 from phase structure measurements, the BLSTPT x ceramics showed enhanced piezoelectric properties: piezoelectric constant d 33  = 516 pC/N, planar electromechanical coupling factors k p  = 57%. The temperature of the permittivity maximum increased with increasing measurement frequency, over the range 302–313 °C, higher than that of conventional relaxor materials such as Pb(B 1 B 2 )O 3 PbTiO 3 systems. The ceramics show relaxor ferroelectric features.