Synthesis, characterisation and thermophysical properties of LaGdCe2O7 ceramic for thermal barrier coatings

In this paper, LaGdCe2O7 ceramic was synthesised by solution reaction method. Its phase composition, microstructure and thermophysical properties were investigated respectively. X-ray diffraction result showed that single phase LaGdCe2O7 with fluorite structure was successfully synthesised. Scanning electron microscopy result revealed that the microstructure of the product was dense and no other unreacted oxides or interphases exist in the interfaces between grains. Its thermal expansion coefficient was higher than that of conventional 8YSZ, while its thermal conductivity was much lower than that of 8YSZ. The lower thermal conductivity of this product was mainly attributed to the differences in atomic weight and ionic radius between solute and host atoms. The results imply that LaGdCe2O7 ceramic can be used as candidate material for the ceramic layer in thermal barrier coatings.