Dielectric properties of BaBi4Ti4O15 ceramics produced by cost-effective chemical method

Abstract

BaBi4Ti4O15, an Aurivillius compound, was synthesized by a cost-effective soft chemical route. The precursor was prepared by precipitating Bi- and Ba-oxalates inside a TiO2 powder suspension. A phase pure orthorhombic BaBi4Ti4O15 was synthesized by heating the precursor powder at 1000 degrees C. The phase formation behavior was investigated using TG-DSC and XRD. Densification behavior of the powder and microstructure development in sintered pellet was examined. Temperature dependent dielectric study of the ceramic has been investigated in the temperature range 300-780 K and frequency range of 1 kHz-1 MHz. The broad dielectric constant peaks at temperature T, was frequency dependent. The dielectric relaxation rate follows the Vogel-Fulcher relation with activation energy = 0.2639 eV, relaxation frequency = 4.95 x 10(21) Hz, and freezing temperature = 620 K. All these parameters indicate that BaBi4Ti4O15 is a relaxor ferroelectric.