Cyclotron Resonance over a wide Temperature Range

By doping the semiconductor with transition group metals such as Fe, Co, or Au, localized states well into the forbidden band may be introduced and, if the carriers are derived from these levels, their number can be maintained reasonably small at temperatures as high as 90 deg K. Using this technique, cyclotron resonance from hole carriers in Ge at temperatures above 90 deg K with microwave radiation of 8.8 mm wavelength were observed. Results obtained from Ge doped with Au are reported over a temperature range from about 4 to 90 deg K. (M.H.R.)