Enhanced Densification and Thermoelectric Performance of In^sub 4^Sn^sub 3^O^sub 12^ by Reactive Sintering in the In-Sn-Ga-O System

• Published in: Journal of the American Ceramic Society 2011-11, Vol.94 (11), p.3733
• Main Authors: Zhou, T, Bhame, S D, Guilmeau, E, Marinel, S, Raveau, B
• Format: Article
• Language: English
• Subjects: Electric properties; Electric resistance; Grain boundaries; Heat conductivity; Sintering
• ISSN: 0002-7820; 1551-2916

The thermoelectric properties of the fluorite-related oxide, ..., have been investigated by studying the system ..., with 0 ≤ x ≤ 0.15. It has been shown that Ga does not enter the ... matrix, and two secondary phases form via the Ga introduction: SnO... and ... By reactive sintering between ..., SnO..., and ... precursors, the density of the samples is considerably increased from 66% (actual density/theoretical density) for x = 0 up to 90% for x = 0.15, which significantly decreases the electrical resistivity. This is attributed to the large number of grain boundaries localized among the secondary phases, which inhibit the grain growth and hence favor the densification. The phase ... is for the first time reported to exhibit a semi-metallic behavior. The Seebeck coefficient does not change significantly with respect to the pristine matrix in accordance with the fact that Ga does not play any role as a doping agent. The thermal conductivity increases with the Ga content. The maximum figure of merit, ZT = 0.23, at 1000 K obtained at a very low Ga content (x = 0.05), is comparable to the value obtained for Ge doped ... (ZT ~ 0.3). This study suggests that ... can be a potential material for thermoelectric applications. (ProQuest: ... denotes formulae/symbols omitted.)