Effects of Dryness on the Calorimetric and Vibrational behavior of (Na2O)x[(B2O3)y(GeO2)1−y]1−x glasses

The two base materials comprising the present ternary, viz., y= 0, i.e., Na2O-GeO binary¹ and y = 1, Na2O-B2O3 binary² have been previously studied and have shown isostatically rigid Intermediate Phases (IPs) to be observed in the x = 0.14 to x = 0.19 range and the x = 0.20 to x = 0.40 range of soda concentration respectively. We had noted earlier that an IP in the present ternary is manifested in the 0.23 < x < 0.30 range of soda. In the present work we have attempted to dry the ternary glasses by vacuum desorbing them while heating close to Tg using a high vacuum pumping line. Re-examination of the reversibility window in the 0.23 < x < 0.30 range of soda shows it to sharpen, get deeper and flatten in the dry glasses providing confidence on the proposed Topological Phases. Raman scattering and IR reflectance experiments are now undertaken to elucidate the role of dryness on glass structure.
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2. K. Vignarooban et al. EPL 108, 56001(2014).