Rare-earth oxides of La2(ZrxCe1 - x) 2O7 for thermal barrier coatings (TBCs) are fabricated via a solid-state reaction at 1600 °C. As the phase formation, microstructure, and thermal properties of these oxides are examined, a fluorite-pyrochlore composite structure is found in the La2(ZrxCe 1 - x)2O7 system. This composite structure is composed of coarse Ce-rich fluorite and fine Zr-rich pyrochlore grains. From XRD and microstructural analysis, the lattice parameter and volume fraction of each phase are evaluated in order to obtain the intrinsic thermal conductivity value of composite-structured oxide with porosity calibration. The thermal conductivity of the composite structure is similar to that of pyrochlore La 2Zr2O7, which is attributed to phonon scattering by phase boundaries.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering