Finite-size-effect on a very large length scale in NBT-based lead-free piezoelectrics

Abstract

Na0.5Bi0.5TiO3-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer applications. We have examined the role of grain size in influencing the structural-polar inhomogeneity of stoichiometric and off-stoichiometric Na0.5Bi0.5TiO3 (NBT), and its morphotropic-phase-boundary (MPB) derivative 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-6BT). Our study reveals that size effect comes into play in these systems on a very large length scale (on the scale of microns) considerably affecting its global structure and properties.