Analysis of the structure of lead borosilicate glasses using laser ionization time of flight mass spectroscopy

Abstract We report on high resolution laser ionization time-of-flight mass spectroscopy (LITOF-MS) measurements of lead borosilicate and sodium-doped lead borosilicate glasses. This technique permits the observation of intermediate range mesounits, and provides new insights into the glass network structure. In lead borosilicates we observed strong mixing of borate and silicate groupings, a likely absence of diborate units, and the formation of boroxol rings with one lead cation (PbB3O6) at borate-rich compositions. The spectra also suggest the growth of a limited lead oxide subnetwork at high Pb contents. In the sodium-doped glasses we see a preference of the sodium for boron units, and the simultaneous appearance of sodium-containing silicate units between 10 and 24 mol% Na2O, though borate association remains predominant. The reedmergnerite unit (BSi4O10) is seen in very small amounts in both glass families.