Ba6−3x Nd8+2x Ti18O54 Tungsten Bronze: A New High-Temperature n-Type Oxide Thermoelectric

• DOI: 10.1007/s11664-015-4275-6
• Publication Date: 2015-12-30T09:40:18Z
• Authors: Feridoon Azough; Robert Freer; Stephen R. Yeandel; Jakub D. Baran; Marco Molinari; Stephen C. Parker; Emmanuel Guilmeau; Demie Kepaptsoglou; Quentin Ramasse; Andy Knox; Duncan Gregory; Douglas Paul; Manosh Paul; Andrea Montecucco; Jonathan Siviter; Paul Mullen; Wenguan Li; Guang Han; Elena A. Man; Hasan Baig; Tapas Mallick; Nazmi Sellami; Gao Min; Tracy Sweet
• Keywords: 02 engineering and technology; Molecular dynamics; 530; 01 natural sciences; Modelling; Titanate; [CHIM] Chemical Sciences; 0103 physical sciences; [CHIM.CRIS]Chemical Sciences/Cristallography; Materials Chemistry; [CHIM]Chemical Sciences; [CHIM.CRIS] Chemical Sciences/Cristallography; Electrical and Electronic Engineering; [CHIM.MATE] Chemical Sciences/Material chemistry; Oxide ceramic; Thermoelectric; [CHIM.MATE]Chemical Sciences/Material chemistry; 540; Condensed Matter Physics; 16. Peace & justice; Electronic, Optical and Magnetic Materials; [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry; TA; Thermal conductivity; Tungsten bronze; 0210 nano-technology

Semiconducting Ba6−3x Nd8+2x Ti18O54 ceramics (with x = 0.00 to 0.85) were synthesized by the mixed oxide route followed by annealing in a reducing atmosphere; their high-temperature thermoelectric properties have been investigated. In conjunction with the experimental observations, atomistic simulations have been performed to investigate the anisotropic behavior of the lattice thermal conductivity. The ceramics show promising n-type thermoelectric properties with relatively high Seebeck coefficient, moderate electrical conductivity, and temperature-stable, low thermal conductivity; For example, the composition with x = 0.27 (i.e., Ba5.19Nd8.54Ti18O54) exhibited a Seebeck coefficient of S 1000K = 210 µV/K, electrical conductivity of σ 1000K = 60 S/cm, and thermal conductivity of k 1000K = 1.45 W/(m K), leading to a ZT value of 0.16 at 1000 K.