Electrical Resistance Anomaly and Hall Effect in (Fe<SUB>1−<I>x</I></SUB>V<I><SUB>x</SUB></I>)<SUB>3</SUB>Al Alloys

Abstract

We have measured the electrical resistivity and the Hall effect in D03-type (Fe1−xVx)3Al alloys with 0≤x≤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 TC and a negative resistivity slope above TC. The tendency of the negative temperature dependence increases markedly with the V composition, accompanying a sharp drop in TC. In particular, the Heusler-type Fe2VAl alloy (x=0.33) exhibits a semiconductor-like behavior with an extremely large resistivity reaching 30 μΩm at 4.2 K. In parallel with the increase in resistivity at low temperatures, the Hall coefficient of the order of 10−8 m3/C also increases rapidly with the V substitution, suggesting a reduction in the carrier concentration.