An XPS study of oxygen bonding in zinc phosphate and zinc borophosphate glasses

X-ray photoelectron spectroscopy has been used to determine oxygen bonding in a series of xZnO · (1 − x)P2O5 (0.50 ≤ x ≤ 0.67) glasses. Curve fitting of the O 1s spectra leads to a quantitative measure of the bridging-to-non-bridging oxygen ratio which is shown to depend on composition according to a simple structural depolymerization model. A third peak, present in the O 1s spectra collected from yB2O3 · (1 − y)Zn(PO3)2 (0.00 ≤ y ≤ 0.40) glasses, is due to oxygens which link borate and phosphate tetrahedra. The relative concentrations of POP, POZn and POB bonds are shown to be in good agreement with a structural model which assumes that borophosphate units (BPO4) form when B2O3 is added to Zn metaphosphate glass.