Phase evolution and relaxor to ferroelectric phase transition boosting ultrahigh electrostrains in (1?x)(Bi1/2Na1/2)TiO3-x(Bi1/2K1/2)TiO3 solid solutions

Owing to the complex composition architecture of these solid solutions, some fundamental issues classical (1?x)Bi1/2Na1/2TiO-xBi1/2K1/2TiO3 (BNT-xBKT) binary system, such as details phase evolution and optimal Na/K ratio associated with highest strain responses, remain unresolved. In this work, we systematically investigated BNT-xBKT solution x ranging from 0.12 0.24 using not only routine X-ray diffraction weak-signal dielectric characterization, but also temperature-dependent polarization versus electric field (P-E) current (I-E) curves. Our results indicate an 81/19 based on high-field electrostrain characterizations. As temperature increased above 100 °C, = 0.19 produces ultrahigh electrostrains (> 0.5%) high thermal stability. The stable were primarily due combined effect electric-field-induced relaxor-to-ferroelectric transition ferroelectric-to-relaxor diffuse during heating. More specifically, revealed relationship between responses characteristic temperatures determined by both weak-field ferroelectric/electromechanical property This work clarifies in solution, paves way for future enhancement through doping strategies.