A novel high-entropy (Sm0.2Eu0.2Tb0.2Dy0.2Lu0.2)2Zr2O7 ceramic aerogel with ultralow thermal conductivity. Issue 21 (1st November 2021)

• Record Type: Journal Article
• Authors: Liu, Debao; Wang, Yiguang; Zhou, Feifei; Xu, Baosheng; Lv, Bowen
• Is Part Of: Ceramics international. Volume 47:Issue 21(2021)
• Page Start: 29960
• Page End: 29968
• Publication Date: 2021-11-01
• Subjects: High-entropy ceramics -- Aerogel -- Rare earth zirconates -- Thermal conductivity; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.07.170
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Here, we report a novel high-entropy rare earth zirconate (HE-REZ) (Sm0.2 Eu0.2 Tb0.2 Dy0.2 Lu0.2 )2 Zr2 O7 ceramic aerogel prepared through a sol-gel template method and high-temperature calcination followed by 3-D-structure reconstruction. The structural evolution and crystallisation behaviour of the prepared aerogel were characterised through scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The results indicated that the as-prepared HE-REZ ceramic aerogels had a typical nanoporous structure. The HE-REZ ceramic aerogels thermally treated at 900 °C presented an ultralow room temperature thermal conductivity of 0.031 W/(m·K), high specific surface areas of 443.26 m 2 /g and a relatively high strength of 12.95 MPa. The effects of different calcination temperatures on the microstructure of the samples were also investigated. Therefore, the excellent insulation performance of these unique HE-REZ ceramic aerogels indicate that they can be used as high-temperature insulators for hypersonic vehicles in the future.