The orbital magnetic susceptibility of two coupled graphite layers is calculated as a function of temperature and Fermi energy ($\mu$). The susceptibility is shown to be diamagnetic at small values of $\mu$, and paramagnetic at large values of $\mu$, with a paramagnetic peak at $\mu \cong {\gamma }_1$, where ${\gamma }_1$ is the interlayer coupling. These results explain the increase in the susceptibility as a function of stage which has recently been observed in ${\mathrm{KC}}_{12n}$.

• Received 2 December 1983

DOI:https://doi.org/10.1103/PhysRevB.30.421