Three-dimensional band structure of graphite studied by angle-resolved photoemission using ultraviolet synchrotron radiation

Angle-resolved photoemission using synchrotron radiation from single crystals of natural graphite is reported for the first time. Direct as well as indirect transitions are observed. The $\pi$ bands and the top of the $\sigma$ bands are obtained with the assumption of a two-dimensional dispersion. A d´etailed discussion of the three-dimensional dispersion is presented for the $\pi$ bands. In the $\Delta$ direction, the normal dispersion is described and leads to an effective mass of $m_{\perp }^{*}=1.2m$. Near the line $P$, the $\pi$ bands are analyzed with use of the Slonczewski-Weiss-McClure model. Numerical values for the parameters within this model are derived. Some general features of the conduction bands at low energy are also given. Finally the experimental results are compared with the band-structure calculations.