Fig. 4: Inverse correlation of m-MRD for Group III’s 13-NAS and 9-CAS glasses.
From: Revealing the relationship between liquid fragility and medium-range order in silicate glasses
a Compositions of CAS (red) and NAS (blue) glasses, with m measured by a DSC method24 (solid symbols) and MRD measured by neutron total-scattering (crossed symbols), as shown in the ternary phase diagram in mol%. b Fragility index (m) is plotted as a function of NBO/T ratio for CAS (red) and NAS (blue) glasses. Room-temperature F(Q)-FSDPs of glasses for CAS (c) and NAS (d) with compositions close to the m-measured ones. The FSDPs of 70 mol% SiO2 glasses are shifted up by 0.5 for clarity. The average MRD-NBO/T correlation of two NAS-lines (blue solid and dotted lines) (e) is used to calculate the MRD values of m-measured NAS glasses. The changing trends of m (b) are inversely correlated with the changing trends of MRD (e). The higher m-values of CAS glasses (b) show lower MRD values (e); the larger m-slope of NAS (b) is also supported by the larger negative MRD-slope for NAS (e).
