Frequency and temperature dependence of actuating performance of Bi1/2Na1/2TiO3-BaTiO3 based relaxor/ferroelectric composites

Abstract

Recently, composites of relaxors (matrix) and either ferroelectric or nonergodic relaxor (seed) were proposed as a solution to resolving one of the main drawbacks of incipient piezoceramics, namely the requirement for high driving electric fields. In this study, we investigate the temperature and frequency dependence of the actuating performance of Bi1/2Na1/2TiO3-BaTiO3-based composites. Apart from the reduction of driving field, the composite architecture offers an extra degree of freedom for tailoring the temperature stability for different operational conditions for actuators. High strain values appear to be sensitive especially to driving frequency. This is originated by the time-dependent process of the coalescence of polar nanoregions. In effect, proximity of driving field and poling field leads to high strain sensitivity. Hence, the driving electric field needs to be adjusted in order to meet the desired frequency specifications for given applications.