Electrical response in poled (Bi_0.5Na_0.5)_0.935Ba_0.065TiO₃ ceramics

Abstract

A ferroelectric material (Bi 0.5 Na 0.5 ) 0.935 Ba 0.065 TiO 3 (BNBT) with a perovskite structure was poled and characterized by electrical impedance spectroscopy as a function of temperature, X-ray diffraction, and Rietveld refinement. The ac conductivity showed a low-frequency dispersion, supporting the idea of heterogeneous potential wells favored by Bi 3þ , Na þ , and Ba 2þ on the A site of the perovskite type of structure. The activation energies for ac conduction depende on the studied frequency. The permittivity and electrical modulus showed a distribution of the relaxation time associated with the delay in the orientation of the dipoles and an important contribution to the short-range conductivity.