Field induced strain response of lead-free BaZrO3-modified Bi0.5Na0.5TiO3–BaTiO3 ceramics

Abstract

Lead-free (0.935−x)[Bi0.5Na0.5TiO3–0.065BaTiO3]–xBaZrO3 (BNBT–xBZ, with x=0−0.07) ceramics were prepared by a conventional solid-state reaction method. The effect of BZ addition on the crystal structure, microstructure, dielectric, ferroelectric and electric field induced strain behavior of BNBT ceramic was investigated. X-ray diffraction patterns of BNBT–xBZ ceramics revealed the formation of single phase perovskite structure in the studied composition range. Addition of BZ in BNBT transform the crystal structure from tetragonal to pseudocubic symmetry. However, with increasing BZ content, the maximum dielectric constant decreased and the dielectric maximum temperature (Tm) shifted towards lower temperature. The field induced strain response of BNBT–xBZ increases from 0.16% for x=0 to 0.38% for x=0.03, at an applied field of 7kV/mm. The corresponding dynamic piezoelectric coefficient for these composition were (Smax/Emax=231pm/V) and (Smax/Emax=542pm/V), respectively. These results suggest that the BNBT–0.03BZ ceramic can be considered as a promising candidate material for piezoelectric application.