Electronic Transport Properties Of Polycrystalline Smxc60

The electrical transport of polycrystalline samples SmxC60 has been investigated by resistivity and magnetoresistance (MR) measurements. The transport mechanism is different for the samples with different x in SmxC60 system. The temperature-dependent resistivity can be explained by the fluctuation-induced-tunneling model for the sample SmC60. The transport properties for the sample Sm2.75C60 appear to be dominated by weak localization (WL) and electron-electron interactions. The MR data of the sample SmC60 cannot be fitted by a weak-localized model with strong electron-electron interactions. The anomalous large MR of the sample SmC60 seems not to be explained by a change within the metallic regions, and could arise from the insulating barriers. [S0163-1829(98)07417-7].