RESUMO
This paper presents the fabrication of a polycrystalline sample of the above electronic system by a mixed-oxide technique. The X-ray diffraction pattern show the evolution of perovskite phase (including some impurity phase). The rhombohedral symmetry and crystallite size of 42 nm were also found from the XRD. The distribution of grains in the microstructure suggests the formation of high density ceramics. The role of grains, grain boundaries and interface on resistive (impedance, electrical modulus and electrical transport) and insulating (dielectric) has been investigated over a wide range of frequencies (103-106 Hz) and temperatures (25-400 °C) using spectroscopy (dielectric, modulus and impedance) techniques. The Nyquist plot illustrates the presence of effects such as grain and grain boundary over selected temperatures. Analysis of conductivity spectra reveals that the electrical transport process of the material is influenced by charge transfer by hopping. The complex modulus spectrum also describes the dielectric relaxation of the material. The study of field dependent polarization reveals the existence of ferroelectricity in the material.
