Magnetoacoustic Study of the Mean Free Path of Electrons in Cadmium and Zinc

Abstract

Using a free-electron model, the temperature and angular variations of the electron mean free path in cadmium and zinc have been determined from magnetoacoustic experiments. The mean-free-path dependence of the high-field saturation attenuation and the ultrasonic open-orbit resonance height were used for investigations in cadmium from 1 to 9°K and in zinc from 1 to 4.2°K. When the data were corrected for the temperature variation of the Debye temperature, it was found that the mean free path varies approximately as $T^{-5\mathrm{}}$ for electrons in closed orbits and as $T^{-4\mathrm{}}$ for electrons in open orbits. Anomalous behavior in the temperature variation is observed below 3°K and seems to be related to the resistance-minimum effect. The interpretation of the angular variation of the mean free path is complicated because cadmium and zinc have Fermi surfaces of more than one sheet, but the data indicate approximately an order-of-magnitude variation over the Fermi surface in both cadmium and zinc.