Abstract
In magnetic fields up to 50 kOe and for photon energies greater than the band gaps for light polarized with Ec and Ec oscillatory changes of reflectivity are observed on ZnO‐crystals at helium temperatures. The anisotropic reduced masses and hole masses and the energy gaps are deduced from the shift of the reflection maxima in dependence on the magnetic field (Hc, Hc). The influence of the Coulomb interaction of holes and electrons and the electron‐phonon interaction on the Landau levels are discussed. The results are compared with the valence band structure of wurtzite type crystals and the band parameters of ZnO previously reported.