Effects of Nb5+ doping on thermal properties of Gd2(Zr1−xNbx)2O7+x ceramics

• Published in: Advances in applied ceramics Vol. 119; no. 4; pp. 212 - 217
• Main Authors: Jiang, Tao, Xie, Min, Wang, Xuanli, Song, Xiwen
• Format: Journal Article
• Language: English
• Published: London, England Taylor & Francis 18.05.2020; SAGE Publications
• Subjects: doping; pyrochlore; thermal properties; Gd2Zr2O7; thermal properties; pyrochlore; Nb2O5 doping
• ISSN: 1743-6753; 1743-6761
• DOI: 10.1080/17436753.2020.1755509

Pyrochlore Gd 2 (Zr 1−x Nb x ) 2 O 7+x (x = 0, 0.05, 0.1, 0.15) ceramic materials were synthesised using a high-temperature solid-state reaction method. The phase structure, thermal expansion coefficient and thermal conductivity of Gd 2 (Zr 1−x Nb x ) 2 O 7+x were investigated in this work. The results show that with the introduction of Nb 2 O 5 , Gd 2 (Zr 1−x Nb x ) 2 O 7+x ceramic materials present a cubic pyrochlore structure. Meanwhile, Gd 2 (Zr 1−x Nb x ) 2 O 7+x ceramics have clear grain boundaries. The thermal expansion coefficient of Gd 2 (Zr 1−x Nb x ) 2 O 7+x ceramic materials reduces from 11.4576 × 10 −6 to 10.7919 × 10 −6 K −1 (larger than 10 × 10 −6 K −1 ), while its thermal conductivity gradually increases with the doping of Nb 5+ ions. Considering their comprehensive properties, Gd 2 (Zr 1−x Nb x ) 2 O 7+x compounds may be considered as promising thermal barrier coatings materials.