Ultrasonic attenuation in HgTe from 2 to 300 K

Abstract

The attenuation of longitudinal ultrasonic waves has been measured in HgTe single crystals between 2 K and room temperature at 100 MHz intervals between 50 and 750 MHz. At low temperatures the attenuation is dominated by damping due to dislocation–phonon interactions and is discussed in terms of the Granato–Lücke model. A large attenuation peak found in the region of 30 to 70 K is consistent with the thermal unpinning of dislocations from vacancies with very low energies.