Intrinsic and extrinsic dielectric responses in BiCu3Ti3FeO12 ceramics

BiCu3Ti3FeO12 ceramics with cubic perovsldte-related crystal structure were prepared by a solid-state reaction method. Both the intrinsic and extrinsic dielectric responses of the ceramics are investigated. When being calcined at 800 degrees C and sintered at 980 degrees C for 20 h, BiCu3Ti3FeO12 ceramics are relatively dense, which exhibit a high intrinsic dielectric constant (similar to 500 at 30 degrees C). Interestingly, a giant permittivity (> 5000) of the ceramics is observed at high temperature, which is attributed to an extrinsic effect. Based on the results of electric impedance and modulus, it can be concluded that the giant permittivity results from the internal bather layer capacitance effect. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.