a- and c-axis resistivity and magnetoresistance in MoCl5 graphite intercalation compounds

The a-axis electrical resistivity rho(a) and the transverse magnetoresistan ce (aT-MR (H parallel to c)) of stage-2 to 6 MoCl5 graphite intercalation c ompounds (GICs) have been measured in the temperature (T) range between 4.2 and 300 K and magnetic field (H) range between 0 and 7 kOe. The data are a nalysed together with the results of c-axis resistivity rho(c) and the long itudinal magnetoresistance (cL-MR (H parallel to c)) reported in our previo us work. For stage-2 to 5 MoCl5 GICs rho(a) shows a metallic-like T depende nce and exhibits no logarithmic behaviour, while rho(c) shows a metallic-li ke behaviour for low stage (2), a logarithmic behaviour for the intermediat e stages (3, 4) and a semiconductor-like behaviour for high stages (5, 6). For all stages the sign of aT-MR (H parallel to c) is positive, while the s ign of cL-MR (H parallel to c) is negative for the intermediate stages (3-5 ) and positive for low stages in low T and weak H. The resistivity rho(c) i s formed of a series connection of G-I-G (G: graphite layer, I: intercalate layer) and G-G resistivity, while rho(a) is formed of a parallel connectio n of each layer contribution. The behaviour difference between rho(a) and r ho(c) is discussed in the light of the role of the interior G layer forming a bottleneck to the c-axis conduction, The logarithmic behaviour and negat ive magnetoresistance in rho(c) arise from the two-dimensional weak localiz ation occurring in these interior G layers.