Microstructure and Thermoelectric Properties of AgSbO3 Ceramics Prepared by Ion-Exchange Powder Synthesis and Normal Sintering
Silver antimonate (AgSbO3) is a potential high-temperature thermoelectric oxide with a low thermal conductivity, but it is difficult to fabricate dense bulk material with high phase purity. Well-dispersed AgSbO3 nanopowder with an average diameter of 50 nm was synthesized by an ion-exchange process in this study, the sintering density of which was apparently enhanced. Nearly single-phase AgSbO3 ceramic samples with a relative density close to 90% were obtained when sintered at a relatively low temperature (1273 K). The electrical conductivity of AgSbO3 increased greatly with increasing sintering temperature, probably because of defects originating from the compositional deviation caused by sintering, in addition to increased density. This study also confirmed that AgSbO3 had a low thermal conductivity, from 1.1 W m−1 K−1 at room temperature to 0.8 W m−1 K−1 at 673 K.