Thermally Induced Metastable Inter-Ferroelectric Phase Switching in Mechanically Biased Single Crystal Relaxor Ferroelectrics

In this work we examine a thermally induced metastable phase transition in mechanically biased piezoelectric [Pb(In_1/2Nb_1/2)O₃]_0.24[Pb(Mg_1/3Nb_2/3)O₃]_0.46[PbTiO₃]_0.32 domain-engineered single crystals. Our results show a purely thermally-driven first order ferroelectric rhombohedral-to-orthorhombic phase transition accompanied by a large, sharp discontinuity in strain while the piezocrystal is held under mechanical compressive bias stress and variable electric field bias. We demonstrate this transition can be cycled repeatedly with a small thermal hysteresis (< 3°C) under zero applied electric field with dynamic reversible strain jump of ~ 0.25 %. Moreover, we show that the thermally driven phase switching behavior can be tuned by varying the bias stress and/or electric field, illustrating the path for establishing effective control parameters and conditions for potential future applications such as actuators, thermoelectric transducers and sensors.