Diamagnetism of Boron and Iodine-Chrolide Compounds of Graphite

Magnetic susceptibilities of compression annealed pyrolytic graphite intercalated with iodine monochloride (ICl) and of pyrolytic carbon substitutionally doped with boron (B) have been measured between 77 K and 300 K as functions of temperature and impurity concentration. The results are discussed in terms of McClure's theory based on the Slonczewski-Weiss band model. A numerical computation of the carrier concentration has led to an evaluation of the hole production rate of impurities; 67% for B and 5% for ICl. The low hole production rate of ICl seems to be ascribed to the clustering of intercalants taking place between carbon layers.