Phase, compositional, structural, and chemical stability of La2Ce2O7 after high temperature heat treatment. Issue 4 (March 2019)

• Record Type: Journal Article
• Authors: Liu, X.Y.; Yi, H.; Che, J.W.; Liang, G.Y.
• Is Part Of: Ceramics international. Volume 45:Issue 4(2019)
• Page Start: 5030
• Page End: 5035
• Publication Date: 2019-03
• Subjects: La2Ce2O7 -- High temperature stability -- Reaction -- ZrO2-CeO2-La2O3; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.11.204
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: High temperature stability of potential materials for thermal barrier coatings becomes increasingly important at elevated temperatures. Therefore, high temperature stability, including phase, compositional, structural, and chemical stability of lanthanum cerate (La2 Ce2 O7, LC) with yttria stabilized zirconia (YSZ) was investigated after heat treatment at 1300 °C. LC was found to possess excellent phase and compositional stability because of unique fluorite structure. In addition, the mole ration between Ce and La elements was close to 1:1 after prolonged high temperature treatment at 1300 °C. However, LC exhibited poor structural and chemical stability due to poor sintering resistance and severe reaction with YSZ. Rapid grain coarsening and pore-healing were observed. Moreover, interdiffusion reaction between LC and YSZ induced by the large difference in Gibbs free energy values led to the formation of pores with high sintering resistance. Two new materials with pyrochlore and fluorite crystal structures were also present in annealed composite samples.