The present thesis deals with the "THERMAL AND ELECTRICALPROPERTIES OF CO-DOPED CERIA BASED MATERIALS FOR SOFCAPPLICATIONS". This work has been carried out in the Department of Physics, Osmania University, Hyderabad. To synthesize the co-doped ceria samples with Sm-Pr, Sm-Y and Sm-Gd codopantswith various doping concentrations through chemical route (sol-gelprocess).2. To characterize the samples through XRD and to evaluate the structure andlattice parameter of the synthesized samples.3. To study the microstructure of the samples with scanning electron microscopy.4. To analyze the chemical composition with energy dispersive spectroscopy(EDS).5. To study the variation of thermal expansion with the temperature.6. To study the impedance response as a function of frequency and temperature.