Influence of Pb doping on the dielectric and electrical behaviour of CaCu3Ti4O12 ceramics

In this work, CaCu3-xPbxTi4O12 (x = 0, 0.1, 0.3, and 0.5 mM) ceramics were prepared using a simple sol-gel method. The PXRD profile was used to examine the material's structure and crystalline nature. HR FE-SEM analysis envisages inhomogeneous ceramic grains with irregular grain shapes and bimodal distributions. It also confirmed that the dopant has a significant impact on grain size. The EDAX spectroscopy study showed the presence of Ca, Cu, Pb, Ti, and O in the materials and also demonstrated their purity and stoichiometric ratios. The dielectric characteristics of various Pb-doped CaCu3Ti4O12 ceramics were studied using impedance spectroscopy over a wide frequency range. According to the findings, adding lead (Pb) to the CCTO mix can assist raise the dielectric constant and reduce the loss factor. The material's dielectric constant exhibits Debye-like dielectric relaxation behaviour, with the value of the dielectric constant decreasing at higher frequencies. The resistivity profile of Pb-doped CaCu3Ti4O12 ceramics shows substantially high magnitudes at lower frequencies when compared to pure CaCu3Ti4O12 ceramics. The complex impedance spectroscopy results suggested that the materials have a positive temperature coefficient of resistance (PTCR) property, which was subsequently investigated using a simple equivalent circuit model. Electrical modulus spectroscopy analysis confirmed the presence of non-Debye relaxation in the synthesised ceramics. This finding suggests that lead (Pb)-doped CaCu3Ti4O12 ceramics could be superior materials for a wide range of microelectronic and energy storage applications.