Doping effects and magnetic instabilities in full-Heusler Fe₂YZ_1-xA_x thermoelectric compounds

Giant thermoelectric power factors have been theoretically predicted on n-doped Fe-based full-Heusler compounds, however, when dealing explicitly with dopants, they may undergo to a magnetic phase transition with a consequent power factor reduction. Using computer experiments, we demonstrate that such transitions is purely related to electronic effects. Exploiting the broader nature of 4d and 5d transition metal orbitals, the appearance of the magnetic instability can be shifted to higher doping regimes, recovering high power factors. The unveiled very large power factors and magnetic fluctuations are fascinatingly very promising respectively for standard thermoelectric and spin-caloritronic device applications.