Giant Dielectric Response and Relaxor Behaviors in Ba0.4Sr0.6(Fe0.5Nb0.5)O-3 Ceramics

摘要

Dielectric relaxations of Ba0.4Sr0.6(Fe0.5Nb0.5)O-3 (BSFN) ceramics were investigated. Two dielectric relaxations with strong frequency dispersion and following the Arrhenius law were detected in low and high temperature ranges, respectively. The low temperature dielectric relaxation was proposed to originate from the electronic ferroelectricity and the high temperature dielectric relaxation was attributed to the defect ordering. The formation mechanism of the giant dielectric constant step was just a competing balance result of the low- and high-temperature dielectric relaxations.