Thermal Damping of Dislocations in Copper and Lead

Abstract

Ultrasonic attenuation measurements were used to study the thermal part of the dislocation damping factor in copper and lead at frequencies between 10 and 90 MHz in the temperature range 1–180°K. With the assumption that the Granato-Lücke theory is correct in the limits of small and large dislocation damping, it was found that the Lothe expression for the dislocation damping factor well describes the temperature variation of the measured attenuation. The frequency dependence of the attenuation was found to be in serious disagreement with the Granato-Lücke prediction.