Thermal expansion of synthetic fused silica as a function of OH content and fictive temperature

A matrix of synthetic fused silica samples with OH contents from 30 to 1300 ppm and of a fictive temperature from 1000 to 1300 °C has been characterized regarding their thermal expansion with high precision. The thermal expansion increases with fictive temperature and drops with OH content. Although fictive temperature and OH are coupled due to the influence of OH on the relaxation of the network, an independent influence of the OH content on thermal expansion has been observed. This may provide a deeper insight into the impact of impurities incorporated into the fused silica network.