Half-Metallic Ferromagnetism and Large Negative Magnetoresistance in the New Lacunar Spinel GaTi3VS8

E. Dorolti (1) , Laurent Cario (2) , Benoît Corraze (2) , Etienne Janod (2) , C. Vaju (2) , H.J. Koo , E. Kan , M.H. Whangbo (3)

1 UBB - Babes-Bolyai University [Cluj-Napoca]
2 IMN - Institut des Matériaux Jean Rouxel
3 NCSU - Department of Chemistry

The lacunar spinel compounds GaTi4-xNxS8 (0 < x < 4), consisting of Ti4-xVx tetrahedral clusters, were prepared and their structures were determined by powder X-ray diffraction. The electronic structures of GaTi4-xVxS8 (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 GaTi3VS8 is a ferromagnetic half-metal, and this prediction was confirmed by magnetotransport experiments performed on polycrystalline samples of GaTi3VS8. 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 GaTi3VS8.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

E. Dorolti, Laurent Cario, Benoît Corraze, Etienne Janod, C. Vaju, et al.. Half-Metallic Ferromagnetism and Large Negative Magnetoresistance in the New Lacunar Spinel GaTi3VS8. Journal of the American Chemical Society, 2010, 132 (16), pp.5704. ⟨10.1021/ja908128b⟩. ⟨hal-00481312⟩