IMPEDANCE SPECTROSCOPIC STUDIES ON ZR-MODIFIED BI3.25LA0.75TI3O12 CERAMICS

N. Thirumal Reddy, K. Madhavi, N. V. Prasad, G. S. Kumar, G. Prasad

Abstract: Zr- modified Lanthanum Bismuth Titanate, La0.75Bi3.25Ti3-xZrxO12 (with x=0, 0.1, 0.3, 0.5, 0.7 and 1.0), ceramics were prepared by the solid-state reaction method. Impedance measurements were made as a function of frequency (100 Hz - 1 MHz), from RT to 550o C. Complex impedance analysis was used as a tool to analyze the electrical behavior of different micro-elemental regions. Cole–Cole plots showed depressed semicircles, which indicate non-Debye relaxation. Different micro-elemental values, namely grain resistance (Rg), grain boundary resistance (Rgb), electrode resistance (Rel) and their capacitance values were evaluated, by using Z-view software. The micro-elemental conductivity Vs Temperature plots showed the linear (Arrhenius) nature, and the activation energies were calculated. The multiple activation process, present in the title compound, was corroborated with the DC–conductivity data and our earlier ferroelectric (P vs. E) results.

Keywords: Impedance, Cole-Cole plots, Arrhenius behavior, Non-Debye.

DOI: https://doi.org/10.15623/ijret.2015.0401060