The Anelasticity of Natural and Synthetic Quartz at Low Temperatures

Measurements of the internal friction in crystals have revealed mechanical relaxation processes which can be attributed to crystal defects. Bordoni 1 first observed a mechanical relaxation of this kind in a number of metals at low temperatures. The amplitude of the absorption was found to be enhanced by cold work and reduced by annealing. Subsequent measurements of the loss in lead by Bommel 2 and in copper by Niblett and Wilks3 served to confirm Bordoni's findings and further to associate the relaxation with the movement of dislocations under the action of an applied shearing stress. Recently, a study of the low-temperature anelasticity in quartz by Bommel, Mason and Warner 4 disclosed two structural relaxation proc* T h i s work has been s u p p o r t e d in p a r t by U. S. A r m y Signal C o r p s C o n t r a c t DA-36-039 sc-64586. T h i s article will be a c h a p t e r in Defect Structure of Quartz and Glass)/ Silica, to be published in 1959 by J o h n Wiley