The phase formation mechanism and kinetics of CaZrO3 from ZrO2 and CaCO3 were investigated by XRD, TEM and thermal quenching method. The results demonstrated that it was CaO decomposed from CaCO3 that reacted with ZrO2, and the size of the final particles was mainly determined by the morphology of the starting ZrO2 particles. Well distributed CaZr0.90In0.10O3-delta (about 130 nm) powders were synthesized at 1000 degrees C. This temperature was comparable to that of the co-precipitation method and 50 degrees C lower than that of the molten salts synthesis process. The relative density of the ceramics fabricated from the powders reached 98% TD at 1400 degrees C, which was 200 degrees C lower than that of the traditional sintering temperature. The ceramics showed satisfactory proton conductivity at moderate temperatures. (c) 2007 Elsevier B.V. All rights reserved.