Bi-doped lanthanum molybdate: Enhancing the anharmonicity and reducing the thermal conductivity using Bi3+ with lone pair electrons. Issue 13 (September 2018)

• Record Type: Journal Article
• Authors: Ok, Kyung Min; Ohishi, Yuji; Mitazono, Yusuke; Muta, Hiroaki; Kurosaki, Ken; Yamanaka, Shinsuke
• Is Part Of: Ceramics international. Volume 44:Issue 13(2018)
• Page Start: 15833
• Page End: 15838
• Publication Date: 2018-09
• Subjects: Thermal barrier coatings -- Crystalline oxides -- Anharmonicity -- Thermal conductivity; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.05.262
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: La2 Mo2 O9 has a considerably low thermal conductivity (0.95 W m −1 K −1 ) at 1273 K, making it an attractive material for thermal barrier coatings. To further reduce the thermal conductivity of La2 Mo2 O9, we focused on the anharmonicity of the lattice induced by lone pair electrons. We substituted the La 3+ site of La2 Mo2 O9 by Bi 3+, which has lone pair electrons, and studied the effect of bismuth doping on the anharmonicity and thermal conductivity of La2 Mo2 O9 . Bismuth doping enhanced the Grüneisen parameter, which is an indicator of anharmonicity, and reduced the thermal conductivity by 24% with respect to non-doped La2 Mo2 O9 at 300 K by substituting with 6 mol% Bi. Theoretical predictions based on the Klemens-Callaway model with experimentally obtained Grüneisen parameters were performed to analyze the thermal conductivity; the reduction in thermal conductivity is mainly attributed to the enhanced anharmonicity provided by Bi substitution.