Characteristics of a granular electronic system in Heusler-type Fe2+xV1-xAl.

We report comprehensive measurements of the magnetic, transport, and thermal properties of the Heusler-type compound Fe2+xV1-xAl, with x values near the ferromagnetic quantum critical point, xc ∼ 0.05. At T ∼ 60 K, a prominent Schottky-like anomaly appeared in the specific heat; this anomaly was correlated with a smaller pseudo-gap formation in magnetic susceptibility, magnetoresistance, and thermoelectric power. Furthermore, a magnetic anomaly observed in the magnetic susceptibility and resistivity at T ∼ 4 K was suppressed significantly by applying a magnetic field. A magnetically inhomogeneous phase arose below T ∼ 60 K, which appeared to consist of ferromagnetic and paramagnetic clusters.