TILT OF N-2 MOLECULES PHYSINTERCALATED INTO C24K AND C24RB

The intercalation of molecular N-2 into C(24)X (X = K, Rb) has been st udied using the nuclear resonance photon scattering (NRPS) technique. We found that, in the physintercalated state, the nitrogen resides in the alkali planes, in a molecular form, with the molecular symmetry ax is almost parallel to the graphene basal planes. In C24K, the N-2 mole cules are only intercalated below 200 K, while in the case of C24Rb, t he physintercalation process starts at room temperature and the amount of intercalated N-2 increases with decreasing T, reaching saturation at around 130 K. These samples were also studied using n-diffraction a nd the N-2 ''small'' diameter, at 120 K, was found to be 0.290 nm in t he (C24K + N-2) system and slightly smaller, 0.279 nm, in the (C24Rb N-2) system. This difference in the measured diameters could also be attributed to a smaller tilt angle of the N-2 molecule in C24Rb as com pared to that in C24K.