Electrical resistance anomaly and Hall effect in (Fe1-Vx)3Al alloys

We have measured the electrical resistivity and the Hall effect in D0(3)-type (Fe1-xVx)(3)Al alloys with 0 less than or equal to x less than or equal to 0.38. When substituted by V, the electrical resistivity increases rapidly at low temperatures and shows an anomalous temperature dependence: an occurrence of a resistance maximum at or near the Curie point Te and a negative resistivity slope above T-C. The tendency of the negative temperature dependence increases markedly with the V composition, accompanying a sharp drop in T-C. In particular, the Heusler-type Fe2VAl alloy (x = 0.33) exhibits a semiconductor-like behavior with an extremely large resistivity reaching 30 mu Omega m at 4.2 K. In parallel with the increase in resistivity at low temperatures, the Hall coefficient of the order of 10(-8) m(3)/C also increases rapidly with the V substitution, suggesting a reduction in the carrier concentration.