Structural, dielectric and electrical characteristics of manganese modified Bi0.5K0.5TiO3 ceramic

Abstract

The manganese modified Bi0.5K0.5TiO3 ceramic (i.e., Bi0.5K0.5Ti0.80Mn0.20O3) was synthesized by a standard solid-state reaction route. Rietveld refinement of X-ray diffraction data confirms that the compound crystallizes in the tetragonal symmetry with P4bm space group. The substitution of 20% Mn ions at the Ti-sites results in a substantial increase in the dielectric constant and a decrease in the dielectric loss in the compound making the material attractive for high-frequency device applications. The analysis of complex impedance and modulus spectroscopy confirms the non-Debye type of relaxation mechanisms in the material with contribution from both the grain and grain boundary to the electrical properties. The AC conductivity data are analyzed to determine the activation energy of the charge carriers participating in the conduction process and to predict the dominant conduction mechanism in the sample.