Thermal conductivity and expansion coefficient of Ln2LaTaO7 (Ln=Er and Yb) oxides for thermal barrier coating applications
Source abstract
Abstract
Abstract Two kinds of novel Ln 2 LaTaO 7 (Ln=Er and Yb) ceramics were prepared via high-temperature solid reaction method. The phase composition, micro-morphology and thermophysical properties were investigated. Results indicate that pure Ln 2 LaTaO 7 ceramics with single fluorite-type structure are synthesized successfully. The thermal conductivities of Er 2 LaTaO 7 and Yb 2 LaTaO 7 are in the range of 1.22–1.43 W/m K and 1.17–1.51 W/m K, respectively, which are much lower than that of YSZ. The lower thermal conductivity can be attributed to the phonon scattering caused by oxygen vacancies and the substituting atoms. The average thermal expansion coefficients of Yb 2 LaTaO 7 and Er 2 LaTaO 7 are 9.94×10 −6 /K and 9.63×10 −6 /K, respectively. As compared with Yb 2 LaTaO 7 , the higher thermal expansion coefficient of Er 2 LaTaO 7 can be ascribed to its lower ionic-bond strength between cations at sites A and B.
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Research context
OpenAlex topics: Nuclear materials and radiation effects · High-Temperature Coating Behaviors · Microwave Dielectric Ceramics Synthesis
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
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