High-temperature transport property of in 2-x Ce x O 3 (0 ≤ x ≤ 0.10) fine grained ceramics

Abstract

Using the spark plasma sintering process In 2-xCe xO 3 (0 ≤ x ≤ 0.10) fine grained ceramics have been synthesized. Our results indicate that all the In 2O 3-based ceramic samples show good electrical conductivity and high thermoelectric power factor. In comparison with pure In 2O 3 bulks or doped samples with grain size above 1 μm, the 100-300 nm fine grain In 2O 3-based ceramics exhibit much lower thermal conductivities (1.9-2.5 W·(m·K) -1 at 1173 K), demonstrating a remarkable cooperative tuning effect imposed by grain size reduction and nano-clusters formation. The maximum figure of merit ZT value is optimized up to ∼0.47 at 1223 K for In 1.92Ce 0.08O 3 sample, which makes them promising candidates for thermoelectric applications. © 2012 The American Ceramic Society.