Effect of Mn doping on the structural, impedance and modulus behaviour of lead free (BaCa)(ZrTiO3) ceramics

Abstract

(Ba0.85Ca0.15)(Zr0.1Ti0.9)1-xMnxO3 ceramics (x = 0.01-0.05) were synthesized via the solid-state reaction method combined with ball milling to investigate their impedance, electrical modulus, conductivity, scaling spectra, and Nyquist behaviour over the temperature range of 250-500 degrees C and frequency range of 1 Hz to 1 MHz. Impedance analysis revealed a continuous decrease in Z ' with an increase in temperature, indicating enhanced charge carrier mobility. Distinct contributions from grains and grain boundaries were observed. Nyquist plots showed two semicircular arcs corresponding to grain and grain boundary contributions relaxation process. Equivalent circuit modeling was employed to interpret the electrical response, and the non-exponential Kohlrausch-Williams-Watts (KWW) function effectively fitted the imaginary part of the electric modulus. AC conductivity varied ranged from 0.002 -0.012 S/m, and the activation energy was increased with Mn doping from the range of 0.8 to 0.9 eV. These findings provide valuable insights into the conduction and relaxation mechanisms, offering a promising route for the development of high-performance materials for flexible energy and storage devices.