title: First-order transition from a Kondo insulator to a ferromagnetic metal in single crystalline FeSi(1-x)Ge(x).
abstract: The phase diagram of FeSi(1-x)Ge(x), obtained from magnetic, thermal, and transport measurements on single crystals, shows a discontinuous transition from Kondo insulator to ferromagnetic metal with x at a critical concentration, x(c) approximately 0.25. The gap of the insulating phase strongly decreases with x. The specific heat gamma coefficient appears to track the density of states of a Kondo insulator. The phase diagram is consistent with an insulator-metal transition induced by a reduction of the hybridization with x in conjunction with disorder on the Si/Ge ligand site.
authors.affiliation: National High Magnetic Field Laboratory (NHMFL), Tallahassee, Florida 32310, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yeo
authors.forename: S
authors.initials: S
authors.lastname: Nakatsuji
authors.forename: A D
authors.initials: AD
authors.lastname: Bianchi
authors.forename: P
authors.initials: P
authors.lastname: Schlottmann
authors.forename: Z
authors.initials: Z
authors.lastname: Fisk
authors.forename: L
authors.initials: L
authors.lastname: Balicas
authors.forename: P A
authors.initials: PA
authors.lastname: Stampe
authors.forename: R J
authors.initials: RJ
authors.lastname: Kennedy