Far-Infrared Cyclotron Resonance in p-Type Tellurium

Cyclotron resonance absorptions of p -type tellurium were investigated at liquid helium temperatures in the far-infrared region from 120µm to 400 µm under the magnetic field up to 92 kOe. The CR transition energies were measured as a function of the magnetic field which was applied parallel to the three main crystal axes of tellurium, c -axis, binary and bisectrix. Fairly good agreements were obtained between the present experiments and the theoretical calculations made by Nakao, Doi and Kamimura (J. Phys. Soc. Japan 30 (1971) 1400. A fine structure was observed in the CR transition peak for H // c -axis, and the relative intensities of the fine structure changed with lowering the temperatures. This fact is possibly due to the unequal spacing of the transition energies along k z -axis between the Landau levels n =0 and 1. The impurity effects in the CR transitions were also measured for the antimony doped specimens with various carrier concentrations. It was found that the binding energy of the impurity state was 1.4 meV in the range of the magnetic field up to 90 kOe.