Dielectric, modulus and impedance spectroscopic studies of nanostructured CaCu2.70Mg0.30Ti4O12 electro-ceramic synthesized by modified sol-gel route

► Nanostructured CaCu2.70Mg.30Ti4O12 was synthesized by modified sol-gel route. ► Ceramic exhibits exceptionally very high εr ∼ 86084 at 1 kHz and 500 K. ► Impedance analysis shows high grain boundary resistance (GB). ► Modulus spectroscopy confirm M.W. relaxation at interface. ► Activation energy for GB relaxation was found to be 0.58 eV.