Anisotropic Relaxation Peak in the Internal Friction of Crystalline Quartz

Abstract

An anisotropic relaxation peak has been observed in the internal friction of crystalline quartz. The height of the loss peak increases by a factor of 2.1 between a sample stressed in the $Y$ direction and one stressed in a direction—18.5° from the $Y$ axis. The shape of the observed relaxation peaks can be fitted by a theory of Zener for a relaxation of a preferred distribution of impurities induced by stress, using an activation energy of 24 kcal/mole and a relaxation time of 0.6×${10}^{-14\mathrm{}}$ sec. The possibility is discussed that this relaxation peak and one observed by Cook and Breckenridge are due to lithium.