Investigation of thermophysical properties of ZrO2-Sm3TaO7 ceramics. Issue 2 (3rd April 2021)

• Record Type: Journal Article
• Authors: Zhou, Ying; Gan, Guoyou; Ge, Zhenhua; Feng, Jing; Peng, Song
• Is Part Of: Journal of Asian ceramic societies. Volume 9:Issue 2(2021)
• Page Start: 629
• Page End: 638
• Publication Date: 2021-04-03
• Subjects: ZrO2-Sm3TaO7 ceramics -- solid-solution mechanism -- thermophysical properties; Ceramics -- East Asia -- Periodicals; Materials science -- Periodicals; 620.1405
• DOI: 10.1080/21870764.2021.1907025
• Languages: English
• ISSNs: 2187-0764

Abstract

ABSTRACT: This study investigates rare earth RE3 TaO7 ceramics and shows that these materials may be optimal for thermal barrier coatings. ZrO2 -Sm3 TaO7 ceramics were prepared through a solid-state reaction. X-ray diffusion and structural refinement revealed a phase structure with an ordered orthorhombic phase for the Ccmm space group. The degree of structural disorder increased with increasing ZrO2 content. Gaussian function fitting of the oxygen 1s X-ray photoelectron spectra showed that the Sm 3+ and Ta 5+ ions were replaced by Zr 4+ ions. At high temperatures, 8 mol% ZrO2 -Sm3 TaO7 has a high thermal expansion coefficient (10.9 × 10 −6 K −1 ). The thermal conductivities of ZrO2 -Sm3 TaO7 (1.17 − 1.75 W·m −1 K −1 ) are lower than those of 7–8 wt.% yttria-stabilized zirconia, while those of 2% ZrO2 -Sm3 TaO7 are the lowest. The oxygen vacancies maintain the charge in equilibrium and enhance phonon scattering while decreasing the thermal conductivity. These results indicate that Sm3 TaO7 can be used as a TBC.