Phase stability, microstructural and thermo-physical properties of BaLn2Ti3O10 (Ln=Nd and Sm) ceramics

The phase stability, microstructural evaluation and thermo-physical properties of BaLn2Ti3O10 (BLnT, Ln=Nd and Sm) ceramics for thermal barrier coating (TBCs) application have been investigated. BLnT (Ln=Nd and Sm) powders is found thermally stable at 1500 °C after exposure for 110 h, and the bulk materials exhibit lamellar structure. BLnT (Ln=Nd and Sm) bulk materials show anisotropy in thermo-physical properties due to the insertion of Ba atoms between [Ln2Ti3O10] (Ln=Nd and Sm) sheets. The thermal conductivities of BLnT (Ln=Nd and Sm) are apparently lower than those of ZrO2–8Y2O3 (8YSZ). Also, BaSm2Ti3O10 exhibits relatively lower thermal conductivity as compared to BaNd2Ti3O10. The thermal expansion coefficient (TEC) of BLnT (Ln=Nd and Sm) is found comparable to that of 8YSZ. BaNd2Ti3O10 exhibits relatively larger TEC than BaSm2Ti3O10. The above results suggest that BLnT (Ln=Nd and Sm) ceramics could be a good potential material for TBC applications.