Temperature dependence of the dislocation drag constant in antimony

Abstract

The over-damped resonance of dislocation segments is investigated in antimony single crystals in the frequency range 7.5 to 172.5 MHz in order to obtain information on the dislocation drag constant. The dislocation part of the losses is separated by two methods, namely by subtracting the internal friction of a crystal before straining from that of the strained crystal and by calculating the value analytically. The dislocation density is determined by etch pit counting. The data of the two methods show a good agreement. The frequency dependence of the internal friction due to dislocation motion is well described by the frequency profile given by the Granato-Lucke theory for an exponential length distribution of dislocation loops. The drag constant is obtained and increases from 6 × × 10−5 dyn s/cm2 at 100 K to 9 × 10−5 dyn s/cm2 at 300 K. The results correspond to a theoretical analysis of the dislocation drag near the Debye temperature due to the joint action of the phonon wind and “slow” phonon relaxation. Temperature dependences are obtained for the dislocation segment lengths in the deformed and non-deformed crystals. [Russian Text Ignored].