Internal friction of SiO2 glasses with excessive and deficient oxygen

The lack of stoichiometry in SiO2 glass causes optical absorption, luminescence and so on. The internal friction of SiO2 glasses with excessive and deficient oxygen was measured in the temperature range of 1.6–250 K. At 35 K excessive oxygen enhanced the intensity of the internal friction of the glass, and deficient oxygen reduced this intensity. These changes of internal friction are analyzed by the bending model related to bridging oxygens in SiOSi bonds. Densitues of both the excessive and deficient oxygen are in the order of 1017/cm3. It is supposed tha the changes in Young's modulus of these glasses are due to the OH contents.