Study of structural, electrical and magnetic properties of 1−x(Ba_0.96Ca_0.04TiO₃)−x(BiFeO₃) ceramics composites

Lead free 1−x(Ba_0.96Ca_0.04TiO₃)−x(BiFeO₃) (abbreviated as BCT–BF) ceramics were prepared by solid state reaction method. The structural studies were carried out by using XRD technique, which confirms that the samples have a tetragonal, with the cubic spinel ferrite phase at room temperature. Dielectric and impedance properties of BCT–BF ceramics have been characterized at different temperature and in 1 kHz–1 MHz frequency range. The complex impedance plot exhibited one semi-circle at higher temperatures. Centers of the semicircles lie below the real axis, which confirms that the material is the non-Debye type. Single semicircle indicating that bulk grain effect are dominated in system. Bulk resistance decreased with the increase of temperature, which indicating the negative temperature coefficient of resistance behavior in our samples. The activation energy determined from an Arrhenius type plot of conductivity (at 1 kHz) was also found to increase from 0.22 eV (x = 0.10) to 1.41 eV (x = 0.30), which is close to half of the optical band gap, suggesting a change in conduction mechanism due to extrinsic defects.