Enhanced thermal stability of dielectric, energy storage, and discharge efficiency in a structurally frustrated piezoelectric system: Erbium modified Na0.5Bi0.5TiO3-BaTiO3

Abstract

We have systematically investigated the effect of rare earth erbium (Er3+) substitution on the structural, ferroelectric, piezoelectric, and dielectric behaviour of the morphotropic phase boundary lead-free piezoelectric 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-6BT). We found that the system shows very good thermal stability of energy density, discharge efficiency, and dielectric permittivity. Detailed structural studies confirmed that Er modification induces a great deal of structural frustration which causes the system to thermally evolve towards the paraelectric state in a very sluggish manner. Our results seem to suggest that, among other factors, this sluggish temperature variation of the structural distortion is an important factor which imparts thermal stability to the energy storage and dielectric properties.