Combustion synthesis of nano-crystalline Bi2/3Cu3Ti2.90Fe0.10O12 using inexpensive TiO2 raw material and its dielectric characterization

Abstract

Nano-crystalline Bi2/3Cu3Ti2.90Fe0.10O12 powder was synthesized using a glycine-nitrate solution-combustion process, and applying inexpensive and stable solid TiO2 powder as the titanium source at relatively lower temperature than conventional ceramic methods. X-ray diffraction pattern confirmed the formation of a single phase of the ceramic sintered at 900°C for 12h. Bright-field transmission electron microscopy of the ceramic revealed that particle size is 16±07nm. Scanning electron microscopy image showed the presences of bimodal distribution of grains and the grain sizes were found to be in the range of, 500nm-1.5μm. Energy dispersive X-ray analyses confirmed the purity and stoichiometry of the ceramic. The frequency-dependent AC conductivity spectra obeyed the Jonscher's power law. The impedance spectroscopy study revealed the presence of grain boundary and electrode effects, which were also proved from modulus spectroscopy. The activation energies for grain boundaries and electrode effects were found to be 0.51 and 0.47eV, respectively. © 2015 Elsevier B.V.