First-principles study of structural, electronic, thermodynamic, and thermoelectric properties of a new ternary half-Heusler alloy PdZrGe

摘要

This work concerns a predictive study of PdZrGe half-Heusler compound with 18 valence electrons. The structural and electronic properties are investigated by using the full potential linearized augmented plane wave (FP-LAPW) method within the framework of generalized gradient approximation (GGA). To investigate the thermodynamic properties, we are applying the quasi-harmonic Debye model. The semi-classical Boltzmann theory as implemented in the BoltzTraP code is used to study the thermoelectric properties. We have found that the PdZrGe alloy is an indirect band gap semiconductor. Also the PdZrGe exhibit a negative thermal expansion. The Seebeck coefficient (S) is relatively high (237 mu V/K at 300 K) due to its semiconducting nature. The calculated thermoelectric figure of merit is 0.759 at 300K; this result indicates that our compound is an excellent candidate for practical applications in the thermoelectric field.