Thermoelectric properties of Fe–V–Al Heusler alloy with excess of Al and deficiency of Fe

The results of the experimental studies of the thermoelectric properties of a Fe$_{1.68}$VAl$_{1.32}$ $p$-type Heuser alloy are presented. A comparison of the electrical resistivity $\rho$ and the Seebeck coefficient $S$ measured in a temperature range 300–475 K with data, published for other Fe–V–Al $p$-type with different chemical compositions, showed that Fe$_{1.68}$VAl$_{1.32}$ has the lowest $\rho$ and one of the highest values of $S$. This leads to one of the record values of the power factor value $PF\approx$ 1.7 mW/(m$^{-1}$ $\cdot$ K$^{-2}$ (at $T$ = 384 K) in Fe$_{1.68}$VAl$_{1.32}$, which is an order of magnitude higher than that in the stochiometric $PF$. The results of thermal conductivity measurements showed high values of $\kappa$ ($\approx$ 11 W/(m$^{-1}$ $\cdot$ K$^{-1}$)) in the studied compound, which is comparable to thermal conductivity of the stochiometric Fe$_2$VAl.