Effect of Thermal Treatments on the Low Temperature Specific Heat of Vitreous Silica

Abstract

During the last few years there have been several experimental attempts to test if the low temperature anomaly of the specific heat of glasses could be sensitive to special physical treatments in order to clear up the structural origin of the excitations responsible for this anomaly. In the case of vitreous silica, the most extensively studied material, irradiation by fast neutrons⁽¹⁾ produced a big variation of the mass density (~ 2 %) and a decrease of 30 % for C_p. However other treatments such as fast electrons irradiation⁽²⁾, strain induced by quenching ⁽³⁾ and thermal treatments⁽⁴⁾, revealed no detectable or small effects.