The charge density wave (CDW) transition temperature in the quasi-one-dimensional (Q1D) organic material $\left(\mathrm{Per}{)}_2\mathrm{Au}\right(\mathrm{mnt}{)}_2$ is relatively low ${(T}_{\mathrm{CDW}}\sim 12\mathrm{K}).\mathrm{}$ Hence in a mean field BCS model, the CDW state should be completely suppressed in magnetic fields of order 30–40 T. To explore this possibility, the magnetoresistance of $\left(\mathrm{Per}{)}_2\mathrm{Au}\right(\mathrm{mnt}{)}_2$ was investigated in magnetic fields to 45 T for $0.5\mathrm{K}<T<\mathrm{}12\mathrm{}\mathrm{K}.$ For fields directed along the Q1D molecular stacking direction, $T_{\mathrm{CDW}}$ decreases with field, terminating at about $\sim 37\mathrm{T}$ for temperatures approaching zero. Results for this field orientation are in general agreement with theoretical predictions, including the field dependence of the magnetoresistance and the energy gap, ${\Delta }_{\mathrm{CDW}}.$ However, for fields tilted away from the stacking direction, orbital effects arise above 15 T that may be related to the return of un-nested Fermi surface sections that develop as the CDW state is suppressed. These findings are consistent with expectations that Q1D metallic behavior will return outside the CDW phase boundary.

• Received 16 July 2003
• Accepted 16 July 2003

DOI:https://doi.org/10.1103/PhysRevB.69.125113