Affiliation: | a Laboratoire National des Champs Magnétiques Pulsés, UMR 5830, 143, Av. de Rangueil, BP 4245, 31432, Toulouse Cedex 4, France b Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caxia Postal 15051 Av. Bento Goncalves 9500, Porto Alegre, RS, Brazil c Laboratoire CRISMAT, UMR CNRS 6508, ISMRA, Boulevard du Mal Juin, 14050, Caen Cedex, France |
Abstract: | We have measured the transport and magnetic properties of the model spin chain single crystal Ca3Co2O6 in high pulsed fields. A crossover between 1D and 3D transport is observed, with the opening of a Coulomb gap below the order temperature of the individual chains. The samples show changes in the variable range hopping transport dimensionality and gap; the magnetic field suppresses the gap, inducing a significant reduction of the resistance, while dimensionality seems governed by temperature. At fields associated with the levels of magnetization of the frustrated triangular lattice formed by the Co lines, and below the critical magnetic temperature, a further increase of the conductivity is observed. This effect is associated with planar magnetic states perpendicular to the lines. |