Thermoelectric properties of FeVSb half-Heusler compounds by levitation melting and spark plasma sintering

Half-Heusler compound FeVSb has been successfully synthesized by levitation melting followed by spark plasma sintering and annealing process. The phase transformation of FeVSb in the fabricating process has been studied, and pure FeVSb half-Heusler phase was obtained. Thermoelectric properties of pure FeVSb with different relative densities have been investigated, and the porosity dependence of thermal conductivity of FeVSb at 300 K follows Maxwell-Eucken equation well. A maximum power factor of 48 × 10−4 W m−1 K−2 was obtained at 350 K from the sample with the highest relative density of 97%. A state-of-the-art ZT value of ∼0.25 has been attained at 550 K for pure FeVSb, which is one of the highest reported ZT value for FeVSb half-Heusler compound. ► Half-Heusler compound FeVSb with different relative densities has been synthesized. ► Phase transformation of FeVSb was confirmed at 1073 K by employing DSC analysis. ► A state-of-the-art ZT value of ∼0.25 has been attained at 550 K for pure FeVSb.