title: Composition induced metal-insulator quantum phase transition in the Heusler type Fe2VAl.
abstract: We report the magnetism and transport properties of the Heusler compound Fe2+x V1-x Al at  -0.10  ⩽  x  ⩽  0.20 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 σ 0 around the critical point, which scaled approximately according to the power law (P  -  P c ) (γ) . 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.
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Naka
authors.forename: Artem M
authors.initials: AM
authors.lastname: Nikitin
authors.forename: Yu
authors.initials: Y
authors.lastname: Pan
authors.forename: Anne
authors.initials: A
authors.lastname: de Visser
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakane
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Ishikawa
authors.forename: Yuh
authors.initials: Y
authors.lastname: Yamada
authors.forename: Motoharu
authors.initials: M
authors.lastname: Imai
authors.forename: Akiyuki
authors.initials: A
authors.lastname: Matsushita