Improvement of Thermoelectric Properties of β-FeSi₂ by the Addition of Ta₂O₅

Abstract

Our goal is the improvement of the thermoelectric properties for FeSi₂. We investigated the improvement of thermoelectric properties, that is, the increase of the power factor and the decrease in the thermal conductivity to add Ta₂O₅. The thermal conductivity of specimens with 1 mass% and 3 mass% of additive decreased to half in comparison with the sample without additive, because phonon scattering was enhanced as a result of an increase in the number of pores in the samples by the influence of Ta₂O₅. The figure of merit for sample with 1 mass% and 3 mass% of additive were higher than that for the sample without additive. The highest performance of the sample with 1 mass% of additive was 2.5×10⁻⁴K⁻¹∼2.8×10⁻⁴ K⁻¹ around 700 K and its dimensionless figure of merit was 0.2 at 700 K.