Interlayer magnetoresistance in the organic superconductor k-„BEDT-TTF...2Cu†N„CN...2‡Br near the superconducting transition

In this paper, we report transport measurements of interlayer magnetoresistance with field parallel and perpendicular to the current direction in the organic superconductor k-(BEDT-TTF)2Cu@N(CN)2#Br. For HiJ , the isothermal magnetoresistance R(H) displays a peak effect as a function of field. While the magnetoresistance at small field can be fitted to stacked Josephson junction model, the negative magnetoresistance is not consistent with quasiparticle tunneling model with a simple mean field gap. The origin for the peak effect remains unresolved. For H'J , R(H) increases monotonically with increasing field. Large magnetoresistance for H'J is consistent with the layered structure of the organic compounds. @S0163-1829~99!03025-8#