title: Half-metallic ferromagnetism and large negative magnetoresistance in the new lacunar spinel GaTi3VS8.
abstract: The lacunar spinel compounds GaTi(4-x)V(x)S(8) (0 < x < 4), consisting of Ti(4-x)V(x) tetrahedral clusters, were prepared and their structures were determined by powder X-ray diffraction. The electronic structures of GaTi(4-x)V(x)S(8) (x = 0, 1, 2, 3) were examined by density functional calculations, and the electrical resistivity and magnetic susceptibility of these compounds were measured. Our calculations predict that GaTi(3)VS(8) is a ferromagnetic half-metal, and this prediction was confirmed by magnetotransport experiments performed on polycrystalline samples of GaTi(3)VS(8). The latter reveal a large negative magnetoresistance (up to 22% at 2 K), which is consistent with the intergrain tunnelling magnetoresistance expected for powder samples of a ferromagnetic half-metal and indicates the presence of high spin polarization greater than 53% in GaTi(3)VS(8).
authors.affiliation: Institut des Materiaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2, rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3, France.
authors.forename: Eugen
authors.initials: E
authors.lastname: Dorolti
authors.forename: Laurent
authors.initials: L
authors.lastname: Cario
authors.forename: Benoît
authors.initials: B
authors.lastname: Corraze
authors.forename: Etienne
authors.initials: E
authors.lastname: Janod
authors.forename: Cristian
authors.initials: C
authors.lastname: Vaju
authors.forename: Hyun-Joo
authors.initials: HJ
authors.lastname: Koo
authors.forename: Erjun
authors.initials: E
authors.lastname: Kan
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Whangbo