A modified oxy-acetylene combustion assisted aerosol-chemical vapor deposition technique operated in atmosphere has been developed and employed to deposit Gd2O3 doped CeO2 thin films with nitrate precursors in the substrate temperature range of 900-1400 degreesC. The compositions of the films are very close to those of mixed precursor solution. The microstructures of the films are strictly influenced by experimental parameters such as substrate temperature, source solution composition and substrate type. A structural zone model is presented to describe the microstructure of the films on poly-crystal line NiO-YSZ as a function of substrate temperature. The ionic conduction activation energy of the films deposited at 1200 degreesC is 66.5 kJ/mol in the temperature range of 450-850 degreesC and 106 kJ/mol over 350-450 degreesC. Also thin films with different microstructures are obtained on various substrates such as poly-crystalline NiO-YSZ, (1 0 0) CeO2 single crystal and (I I I) Si single crystal. (C) 2003 Elsevier Science B.V. All rights reserved.