12 Ceria-yttria stabilized zirconia (CYSZ) coatings were prepared by air plasma-sprayed on the nickel alloy. The as-sprayed CYSZ coatings and heat-treated CYSZ coatings were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The XPS data indicated the coexistence of Ce3+, Ce4+, Y3+ and Zr4+ ions near the surface of the as-sprayed CYSZ coatings and the disappearance of Ce3+ ions in the CYSZ coatings after thermal treatment at 1000 degrees C for 15 h. From the XRD patterns, the solid solution of CeO2-Y2O3-ZrO2 formed in the CYSZ coatings because of the lack of any features from Y2O3 and ZrO2 single phases. After thermal treatment, the main phases of all the samples were consistent with the characteristic peaks of cubic ZrO2. (C) 2009 Elsevier B. V. All rights reserved.