FIELD-INDUCED CHANGE OF THE OSCILLATION SPECTRUM AND ANGLE DEPENDENCEOF THE MAGNETORESISTANCE IN THE QUASI-2-DIMENSIONAL ORGANIC SUPERCONDUCTOR (BEDO-TTF)(2)REO4-CENTER-DOT-H2O

Transverse magnetoresistance of the two-dimensional organic supercondu ctor (BEDO-TTF)(2)ReO4 . H2O has been measured in pulsed magnetic fiel ds up to 52 T with different orientations. In low fields, applied perp endicularly to the conducting plane, the data are in good agreement wi th previous studies: the two Shubnikov-de Haas oscillation series attr ibuted to electron and hole orbits, respectively, are observed. Howeve r, a new oscillation series rises up at high magnetic field. Furthermo re, magnetic fields higher than 10 T and applied parallel to the condu cting planes yield negative magnetoresistance. These features are disc ussed on the basis of the Fermi surface calculations. (C) 1998 Elsevie r Science B.V. All rights reserved.