MILLIMETER EPR SPECTROMETER FOR STUDYING THE HIGH-CONDUCTIVITY SAMPLES

摘要

The zero-gap semimagnetic semiconductors with the resonant donor level and mixed-valence are of fundamental and applied interest. The high mobility of band electrons in them allows one to use almost the entire arsenal of modern methods and means for studying the physical properties of solids. One of the effective methods of studying the magnetoresonance properties of such semiconductors is the electron paramagnetic-resonance method. However, due to the high conductivity of semiconductors like those, the sensitivity of applied spectrometers should be increased. For the most part the sensitivity is determined by the electromagnetic properties oj the resonance cell being used. The problem becomes more difficult for investigations in the mm wavelength short-wave region where the skin depth is of a few microns only. In order to extent the operating temperature range the functional parts of the electron paramagnetic resonance spectrometer were modified. Also, an original resonant cell in the form of two-mirror open resonator for recording the absorption spectra of various substances in the mm wavelength short-wave region within the temperature limits T = 1.7...300 K was developed. The electron paramagnetic resonance spectra for the zero-gap semimagnetic semiconductor HgSe:Fe measured at a frequency of 123 GHz are shown. These spectra illustrate the advantages of the proposed resonant cell in the spectrometer structure for investigations of the high-frequency magnetic-resonance properties of high-conductivity materials.