Microwave Faraday rotation in some anisotropic n-type germanium samples at room temperature

Abstract

Faraday rotation measurements have been performed at room temperature on antimony-doped n-type single crystals of germanium, cut in the (110) plane, with a magnetic field up to 0·9 T applied in the [110] direction, and with the direction of polarization parallel to the [11bar above 1] direction using 9·0 GHz radiation. Rotation is measured on samples with resistivities from 10 Ω cm to 0·5 Ω cm, and is found to increase linearly with the magnetic field up to about 0·7 T. These rotation measurements are compared with the theory developed by Donovan and Webster in the early 1960's for anisotropic semiconductors. The agreement between the measured and calculated values of the Faraday rotation is quite good for the sample with resistivity of about 9 Ω cm, but in the case of other higher conductivity samples, the measured Faraday rotation is found to be much smaller than the calculated values. The probable causes for this discrepancy are mentioned briefly.