Anisotropic magnetoresistance in the organic superconductorβ″−(BEDT−TTF)2SF5CH2CF2SO3

In this paper, we report transport measurements of interlayer magnetoresistance with field parallel and perpendicular to the current direction in an all organic superconductor ${\beta }^{″}-{\mathrm{}(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}-\mathrm{T}\mathrm{T}\mathrm{F})\mathrm{}}_2{\mathrm{SF}}_5{\mathrm{CH}}_2{\mathrm{CF}}_2{\mathrm{SO}}_3.$ For $H\parallel I,$ the isothermal magnetoresistance $R\left(H\right)\mathrm{}$ at low temperatures $(T<~T_c)$ displays a peak effect as a function of field. For $H\perp I,$ $R\left(H\right)\mathrm{}$ increases monotonically with increasing field. The results are very analogous to the interlayer magnetoresistance in $\kappa -(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}-\mathrm{T}\mathrm{T}\mathrm{F}{)}_{2}X$ compounds. The observation of the peak effect or negative magnetoresistance in different systems for $H\parallel I\perp$ plane suggests that it is intrinsic to the layered organic superconductors. For $H\perp I,$ the large positive magnetoresistance is in a general agreement with a two band model for charge transport.