Ultrasonic studies of the electronic structure of hexagonal metal crystals III. Shear wave attenuation in magnesium, zinc and cadmium

Measurements have been made of the electronic attenuation x of shear waves in pure magnesium, zinc and cadmium crystals. In the high-frequency limit x is proportional to the frequency of the sound v and values of N = lim (x/v) for propagation along the <1120> and <1010> directions, with the polarization vectors also in the basal plane, were obtained. These agreed well with theoretical calculations based on the Fermi surface geometry; a striking feature was the strong anisotropy in zinc and cadmium, but not in magnesium.