Characterization of the High‐Temperature Ferroelectric (100− x − y ) BiScO 3 –( x ) Bi ( Zr 0.5 Zn 0.5 ) O 3 –( y ) PbTiO 3 Perovskite Ternary Solid Solution

Ternary compositions based on Bi (B′B″) O 3 – PbTiO 3 ‐type compounds have been investigated for high‐temperature piezoelectric applications. Compositions in the ternary were chosen to be near the binary morphotropic phase boundary ( MPB ) composition of BiScO 3 – PbTiO 3 ( BS – PT ). Ternary compositions in (100− x − y ) BiScO 3 –( x ) Bi ( Zr 0.5 Zn 0.5 ) O 3 –( y ) PbTiO 3 [(100− x − y ) BS – x BZZ – y PT ] have been investigated with x  ≤ 7.5. For compositions with x  > 10, the Curie temperature ( T C ) decreased below 400°C. Dielectric, piezoelectric, and electromechanical properties were characterized as a function of temperature, frequency, and electric field. Small additions of BZZ were shown to increase the electromechanical properties with only a small loss in T C . The electromechanical properties were temperature stable up to the depoling temperature. The most promising composition exhibited a T C of 430°C, piezoelectric coefficient ( d 33 ) of 520 pC/N, and a planar coupling factor ( k p ) of 0.45 that remained unchanged up to depoling temperature at 385°C.