Enhanced Electromechanical properties of ferroelectric Bi1/2Na1/2TiO3 −7BaTiO3/relaxorBi1/2Na1/2TiO3 −25SrTiO3composites

Ceramic-ceramic composites are an established approach to tuning properties of piezoelectric materials [1], [2]. The aim of this work is the investigation of the ferroelectric properties of a composite of ergodic relaxor BNT-25ST (matrix) and non-ergodic relaxor BNT-7BT (seed), in the hopes that such a composite will provide enhancement of unipolar strain, while minimizing the hysteresis behaviour, two parameters important for actuator applications. Our results show that the electromechanical behavior of layered and mixed composites as a function of composition parallel each other, however for both unipolar and bipolar fields, the maximum polarisation and strain is obtained with mixed composites. Maximum unipolar strain enhancement was observed in the 10% mixed composite and it is predicted that higher enhancement could be obtained with an even lower amount of seed.