Large electrostrictive strain in (Bi_0.5Na_0.5)TiO ₃-BaTiO₃-(Sr _0.7 Bi _0.2) TiO ₃ solid solutions

Relaxor ferroelectrics (0.94 - x)(Bi_0.5Na_0.5)TiO ₃-0.06BaTiO_3-x(Sr_0.7Bi _0.2□_0.1)TiO₃ (BNT-BT-xSBT) (0 ≤ x ≤ 0.5), were prepared by a solid-state reaction process, and their structures were characterized by the transmission electron microscopy and Raman spectroscopy. The BNT-BT-0.3SBT has a very high electrostrictive strain S = 0.152% with hysteresis-free behavior, much more than the reported S in other ferroelectrics. S-P² profiles perfectly follow the quadratic relation, which indicates a purely electrostrictive effect with a high electrostrictive coefficient (Q₁₁) of 0.0297 m⁴/C². Even, its Q₁₁ keeps at a high level in the temperature range from ambient temperature to 180°C. The field-induced large electrostrictive strain of BNT-BT-0.3SBT was attributed to the existence of ferroelectric nanodomains.