Electronic, Structural, Thermodynamic, and Mechanical Stabilities, Half-Metallicity, and Thermoelectric Performances of CE-Based Half-Heusler

The method of linearized full-potential augmented plane waves based on density functional theory (DFT) is employed to investigate the structural, elastic, magnetic electronic, and thermoelectric properties of the cerium-based half-Heusler alloy FeCeSi. The exchange correlation functional is treated with the generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA-PBE) and the Tran-Blaha-modified Beck-Johnson (TB-mBJ) as implemented in the Wien2k package. According to our results, we have discovered that the material studied is mechanically stable, which means that this compound can be synthesized experimentally. Furthermore, FeCeSi exhibits a half-metallic behavior obeying the Slater-Pauling rule with an integer magnetic moment of 2 μB. The electronic band structures and density of states confirm the half-metallic character with an indirect band gap equals to 0.51 eV and 0.59 eV for GGA-PBE and TB-mBJ approximation, respectively. For the study of the thermoelectric parameters, such as Seebeck coefficient (S), electrical conductivity (σ), thermal conductivity (κ), and figure of merit (ZT), the Boltzmann transport equations within the framework of DFT have been used. Significant values for the figure of merit and Seebeck coefficient indicate promising candidate for useful thermoelectric applications for FeCeSi alloy. So far, no experimental or theoretical investigations have been carried out on the half-Heusler alloy FeCeSi. Accordingly, our theoretical results concerning structural, elastic, electronic, magnetic, and thermoelectric properties will probably be confirmed by experimental investigations.