Semiconductorlike Behavior of Electrical Resistivity in Heusler-type Fe2VAl Compound

An anomalous negative temperature dependence of electrical resistivity has been observed in (Fe1-xVx)3Al alloys with V compositions up to x = 0.35. In particular, the Heusler-type Fe2VAl compound is found to be on the verge of magnetic ordering and to exhibit a semiconductorlike behavior with the resistivity reaching 3000 μΩ cm at 2 K, in spite of the possession of a clear Fermi cutoff as revealed in photoemission valence-band spectra. A substantial mass enhancement deduced from specific heat measurements suggests that Fe2VAl is a possible candidate for a 3d heavy-fermion system