Electronic and thermoelectric properties of Fe2VAl: The role of defects and disorder

Using first-principles calculations, we show that Fe2VAl is an indirect band-gap semiconductor. Our
calculations reveal that its semimetallic character (which is sometimes assigned) is not an ntrinsic property but originates from magnetic antisite defects and site disorder, which introduce localized in-gap and resonant states changing the electronic properties close to the band gap. These states negatively affect the thermopower S and the power factor equal to S2σ, decreasing the good thermoelectric performance of intrinsic Fe2VAl.