Heat capacity measurements by DSC in the glass transition domain of BO1.34Fo.32 glass have allowed the determination of two glass transition temperatures Tg on heating up to (Tg+80)K. This result is in good agreement with a previous structural characterisation of a BO1.32F0.36 glass by NMR, thus demonstrating the appearance of new polyhedral species near Tg and the formation of BF3 trapped in the glass matrix. The difference between the heat capacities of the solid and the liquid phases, 0.8J/gK, reveals the fragile character of the melt.
Origin
Inst Science, France
Journal Title
Phys Chem Glasses 45 4 2004 223-226
Sector
Special Glass
Class
S 2868