High mechanical and thermoelectric performances in hot-pressed CdO

摘要

Abstract High density bulk CdO polycrystalline thermoelectric ceramics have been prepared through a hot-pressing process. Density measurements have revealed that it reaches 99.5% of the theoretical one, in agreement with the observed microstructure. Microhardness has shown to have indentation size effect, decreasing when the load is raised. Electrical resistivity shows metallic-like behaviour until 650 ℃ and semiconducting-like one at higher temperatures while Seebeck coefficient increases in the metallic-like region and decreases in the semiconducting one. The maximum power factor values, 1.6 mW/K~2m, have been achieved at about 650 ℃. These values are the highest obtained in this family of materials, with the advantage of its low thermal treatment duration, when compared with the typical solid state sintering process.