Composition induced metal-insulator quantum phase transition in the   Heusler type Fe2VAl
  We report the magnetism and transport properties of the Heusler compound Fe2+xV1-xAl at -0.10 < x < 0.10 under pressure and a magnetic field. A metal-insulator quantum phase transition occurred at x = -0.05. Application of pressure or a magnetic field facilitated the emergence of finite zero-temperature conductivity around the critical point, which scaled approximately according to the power law. At x < -0.05, a localized paramagnetic spin appeared, whereas above the ferromagnetic quantum critical point at x = 0.05, itinerant ferromagnetism was established. At the quantum critical points at x = -0.05 and 0.05, the resistivity and specific heat exhibited singularities characteristic of a Griffiths phase appearing as an inhomogeneous electronic state. 
Takashi Naka, Artem M. Nikitin, Yu Pan, Anne de Visser, Takayuki   Nakane, Fumihiro Ishikawa, Yuh Yamada, Motoharu Imai, Aki...
cond-mat.str-el