A typical composition of the system Ce1-xGdxO2-delta with x = 0.15 (CGO15) has been synthesized by auto-combustion method. DTA/TGA of the precursor compound indicated the completion of reaction at about 270 degrees C. Greater than 95% of the theoretical density has been achieved by sintering at 1300 degrees C for 10 h. Single phase formation in as-burnt stage has been confirmed by its powder X-ray diffraction (XRD) pattern. The structural morphology was studied employing bright field transmission electron micrograph (BFTEM) and high resolution transmission electron micrograph (HRTEM). BFTEM image indicates that particles are highly agglomerated and appear to be dispersed in amorphous matrix. Also BETEM image reveals that the average particle size is 26 +/- 5 nm. The presence of amorphous phase in as-prepared ash was also confirmed by HRTEM and selected area diffraction (SAD). The scanning electron micrograph (SEM) of the thermally etched system shows grains having an average size of 400 nm. Impedance measurements have been made in the frequency range 1 Hz to 1.3 MHz between 200 and 500 degrees C and the total conductivity was measured. An enhanced conductivity value is observed which may make this system suitable for application as a solid electrolyte material for intermediate temperature solid oxide fuel cells (IT-SOFCs). (C) 2010 Elsevier B.V. All rights reserved.