Low-temperature internal friction of deformed germanium and silicon

Abstract

The internal friction of deformed germanium and silicon single crystals was investigated in the temperature range from 10 to 450 °K at a frequency of 15 Hz. The oscillation amplitude was varied in a range from ε = 5 × 10−5 to 1 × 10−3. No maximum of the internal friction was observed which could be associated with the motion of dislocations. The internal friction was found to be independent of orientation and of dislocation density. This result can be explained with the assumption of a short free dislocation segment length L (< 100 b). The consequences are discussed.