Ultrasonic Attenuation in Tin Single Crystals at Low Temperatures

抄録

The ultrasonic attenuation coefficient and velocity in the superconducting and the normal states of tin single crystals were measured at temperatures between 1.5° and 4.2°K. It was found that (1) the anisotropy of ultrasonic attenuation in different crystallographic directions exists in the case of comparatively long wavelengths (the product of the mean free path of conduction electrons and wave number of sound waves is less than unity). (2) Also the ratio of longitudinal to shear wave attenuation was found to be larger than that predicted from the free electron model.