CHEMICAL-STRUCTURE OF LITHIUM SILICOPHOSPHATE GLASSES

We have investigated the chemical structure of a series of lithium sil icophosphate glasses by means of X-ray photoelectron spectroscopy (XPS ). The fine structure of the oxygen Is spectrum was analyzed in terms of three contributions due to bridging (BO), non-bridging (NBO) oxygen , and oxygen (BO6) linking an uncharged PO4 tetrahedron with a double charged SiO62- octahedron. The relative fractions and the mean binding energies of BO, NBO and BO6 have been determined as a function of the glass composition, especially the modifying cation concentration. The results are discussed in view of the nuclear magnetic resonance spect roscopy of the same lithium silicophosphate glasses. (C) 1997 Elsevier Science B.V.