X-ray photoelectron spectroscopic studies of molybdenum phosphate glassy system

X-ray photoelectron spectroscopy has been applied to molybdenum phosphate glasses and the core-level binding energies of P 2p, Mo 3d52 and O 1s electrons have been measured. The O 1s spectrum is deconvoluted into two peaks and the variation in the peak areas is discussed in terms of an existing structural model. According to this model, oxygen in the glass is present in some or all of the following structural units depending on its composition: P=O, POP, POMo, MoOMo, MoO and . Oxygen atoms in all structural units are found to contribute to the lower binding energy peak, except those in POP which contribute to the higher binding energy peak. The binding energy of P 2p is found to decrease with the addition of MoO3 to P2O5, saturating near the metaphosphate compositions, while that of Mo 3d52 varies only slightly with composition. Rupture of the PO bonds and changes in the next nearest neighbour environment of the P and Mo atoms are believed to account for these changes.