Figure 1.

Experimental ³¹P MAS NMR spectra recorded from Na₂O–CaO–SiO₂–P₂O₅ glasses, where the BG(2.5) and BG(2.9) series are displayed in the left and right columns, respectively, and ordered according to increasing P₂O₅ contents from top to bottom. The peak maximum is specified at the outermost portion of each spectrum; it is mainly dictated by the ³¹P resonances from Q_P⁰ groups, whose traces are not indicated, except for the NMR spectrum from BG_6.0(2.9) that required deconvolutions into two distinct ³¹P signals. Shaded areas mark signal contributions from Q_P moieties, whose relative populations (in %) are indicated. The curve beneath each spectrum reveals the difference between the experimental and best-fit spectra.