Complete set of material constants of 0.95(Na_0.5Bi _0.5)TiO₃-0.05BaTiO₃ lead-free piezoelectric single crystal and the delineation of extrinsic contributions

Lead-free piezoelectric single crystal 0.95(Na_0.5Bi _0.5)TiO₃ (NBT)-0.05BaTiO₃ was grown by top-seeded solution growth method, which has rhombohedral symmetry with composition near morphotropic phase boundary. Full set of dielectric, piezoelectric, and elastic constants for [001]_c poled domain-engineered single crystal was determined. Excellent electromechanical properties and low dielectric loss (d₃₃ = 360 pC/N, d₃₁ = -113 pC/N, d₁₅ = 162 pC/N, k₃₃ = 0.720, k_t = 0.540, and tan δ = 1.1%) make it a good candidate to replace lead-based piezoelectric materials. The depolarization temperature (T_d = 135 °C) is the highest among all NBT-based materials and its electromechanical coupling properties are very stable below T_d. Extrinsic contributions to piezoelectric properties were investigated by Rayleigh analysis.