Preparation and thermal properties of Sm2AlTaO7

摘要

In this work, the Sm_(2)AlTaO_(7) was synthesized by solid reaction method, and its phase composition, microstructure, and thermophysical properties were investigated. XRD results show that pure Sm_(2)AlTaO_(7) with single pyrochlore-type structure is prepared successfully. The thermal conductivity of Sm_(2)AlTaO_(7) at 1,273?K is about 1.13?W?m~(?1)?K~(?1), which is much lower than that of YSZ. The low thermal conductivity can be attributed to the phonon scattering caused by substituting atoms. Its thermal expansion coefficient is lower than that of Sm_(2)Ce_(2)O_(7), but close to that of YSZ. There is no phase transformation occurred between 293 and 1,673?K. The excellent thermophysical property means that the Sm_(2)AlTaO_(7) has potential to be used as candidate ceramic material for thermal barrier coatings.