SEMICONDUCTOR-LIKE BEHAVIOR OF ELECTRICAL-RESISTIVITY IN HEUSLER-TYPEFE2VAL COMPOUND

An anomalous negative temperature dependence of electrical resistivity has been observed in (Fe1-xVx)(3)Al 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 semiconductorlik e behavior with the resistivity reaching 3000 mu Omega cm at 2 K, in s pite of the possession of a clear Fermi cutoff as revealed in photoemi ssion valence-band spectra. A substantial mass enhancement deduced fro m specific heat measurements suggests that Fe2VAl is a possible candid ate for a 3d heavy-fermion system.