High-Performance Sm-Doped Pb(MgNb)O-PbZrO-PbTiO-Based Piezoceramics.

High-performance piezoelectric materials are pivotal to many electromechanical applications including piezoelectric actuators, sensors, and transducers. However, the general approach to achieve high piezoelectric properties by establishing morphotropic phase boundary (MPB) has limitation due to the weak anisotropy of the Gibbs free energy profile at the MPB region. Here, aliovalent Sm-doped 0.4Pb(MgNb)O-(0.6-)PbZrO-PbTiO piezoelectric ceramics were fabricated by a solid-state method, where the optimized piezoelectric coefficient = 910 pC/N, dielectric constant ε = 4090, and Curie temperature = 184 °C were obtained at = 0.352, being attributed to the synergistic contributions from the MPB and enhanced local structural heterogeneity. Rayleigh analysis was adopted to study the intrinsic and extrinsic contributions in Sm-doped PMN-PZ-PT ceramics, where the extrinsic contribution was found to be on the order of 25-67% at 4 kV/cm. Of particular significance is that a large signal * = 820 pm/V (at 20 kV/cm) with a minimal strain variation of 5% was achieved for a composition of = 0.372 over the temperature range of 20-160 °C, being superior to those previously reported piezoelectric ceramic materials. This work offers a good paradigm to simultaneously achieve high piezoelectric properties with good temperature stability in ferroelectric ceramics, which have great potential for piezoelectric application at elevated temperatures.