Novel approaches for controlling stage structure of metal chloride–graphite intercalation compounds

Intercalation of EuCl3 TbCl3, and AlCl3 into graphite was carried out in the presence of chlorine. The observation of products by x-ray diffraction showed that the extent of chloride intercalation could be controlled through adjustment of the pressure of chlorine; increasing pressure tended to increase the extent of intercalation. In the case of EuCl3, the extent of intercalation varied to show a stage transition. In contrast, TbCl3 intercalation gave a mixture of stage 2 or stage 4 graphite intercalation compound (GIC) and remaining graphite, where the extent of intercalation is revealed by the ratio of GIC to graphite. With respect to AlCl3 intercalation, although the preparation of stage 1, 2, and 4 GICs was successful, stage 3 and 5 GICs could not be obtained.