MAGNETOOPTICAL EFFECT OF THE WANNIER EXCITON IN A BIAXIAL ZNP2 CRYSTAL .3.

We have measured reflection and absorption spectra of ZnP2 monoclinic crystal in different magnetic fields up to 40 T at 4.2 K. From anisotropic properties of the exciton structures it is suggested that a bottom of the conduction band and a top of the valence band consist of s-like and pz-like electrons, respectively. This suggestion is supported by anisotropy in paramagnetic splittings. Especially, a g-factor of 4.0 leads to a conclusion that an isotropic crystal field is much larger than a spin-orbit splitting for the valence electron. Moreover, the diamagnetic shifts of the n=1 exciton line in the different orientations of the magnetic fields are reported and compared to those of the n=2 line previously reported. © 1990, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.