Re-entrant relaxor–ferroelectric composite showing exceptional electromechanical properties

Thermal stability, precision, and large output are desired for applications of electromechanical materials. However, this combination has been hardly attained because both the commercially used materials and currently promising candidates are confronted with a critical challenge: the intrinsic incompatibility among the broad temperature window, low hysteresis, and high strain. Here we report a re-entrant relaxor–ferroelectric composite that solves this long-standing challenge: a combination of low hysteresis and large electrostrain over a broad temperature range (i.e., a 168-K temperature window for hysteresis <20% and strain >0.1%) in sufficiently disordered (Ba0.925Bi0.05)(Ti1？x/100Snx/100)O3 ceramics. In situ transmission electron microscopic observations and permittivity measurements reveal the existence of a re-entrant anomaly that guarantees the relaxor–ferroelectric microstructure over a broad temperature range and the resulting combination of exceptional properties. Our finding of a re-entrant relaxor–ferroelectric composite not only solves the incompatibility of the electromechanical properties but may also open a way to develop thermally stable high-performance materials