Dielectric properties of nanocomposite based on bismuth copper titanate

Abstract

0.6Bi2/3Cu3Ti4O12–0.4BaTiO3 (BC-BT) nanocomposite has been successfully synthesized by modified solid-state route. Powder X-ray diffraction confirms the formation of Bi2/3Cu3Ti4O12 and BaTiO3 at 870 °C. Particle size observed by TEM is 70 ± 10 nm. Atomic force microscopy imaging of composite shows statistically significant changes in the surface roughness. Magnetic behavior of the composite shows the weak ferromagnetic nature in M-T and M-H curve. Magnetic study of composite indicates a transition from ferromagnetic to paramagnetic. The nanocomposite exhibits improvement in dielectric loss (tan δ ≈ 0.09) at 1 kHz and 50 °C. The low-frequency performance of the composite was estimated by measuring the frequency dispersion of the dielectric constant (ɛ′) and dielectric loss (tan δ). The AC conductivity spectrum obeyed the Jonscher power law, and exponent values (s) were found to be 0.40–0.51 for the BC-BT composite. The grain resistance (Rg) of BC-BT nanocomposite was found to be 37.30 Ω sintered at 870 °C for 12 h. Composite impedance spectroscopic studies expose that the electrical relaxation process was temperature dependent. © 2017, Australian Ceramic Society.