Effects of Inherent Electric and Anisotropic Forces on Raman Spectra in α -Quartz

Measurements with improved precision of the width, intensity, and position of all the Raman-active lines of α-quartz have been made; the results are more extensive than those previously reported. With the accuracy achieved, we can for the first time quantitatively determine the relative values of the Raman tensor elements for all lines, and the relative importance of the long-range electric force and the force due to the crystal anisotropy. The effect of the inherent electrooptic contribution to the scattering is studied for various E vibrations.