title: Molybdenum modified phosphate glasses studied by 31P MAS NMR and Raman spectroscopy.
abstract: Glasses have been synthesized in the system P2O5-SiO2-K2O-MgO-CaO modified by addition of MoO3. Glasses were prepared by conventional fusion method from 40 g batches. The influence of Mo-cations on the analysed glass structure was investigated by means of Raman and (31)P MAS-NMR techniques. It has been found that molybdate units can form Mo[MoO4/MoO6]-O-P and/or Mo[MoO4/MoO6]-O-Si bonds with non-bridging oxygens atoms of Q2 methaphosphate units, resulting in the transformation of chain methaphosphate structure into pyrophosphate and finally into orthophosphate structure. It has been also found that increasing amount of MoO3 in the structure of investigated glasses causes their gradual depolymerization and molybdenum ions in the analysed glass matrix act as modifying cations.
authors.affiliation: Department of Ceramics and Refractories, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Kraków, Poland. Electronic address: mszumera@agh.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Szumera
mesh_terms: D005898:Glass / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008982:Molybdenum / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D058105:Polymerization; D017640:Silicates / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D010710:Phosphates; D017640:Silicates; D008982:Molybdenum
keywords: (31)P MAS NMR spectroscopy; Molybdenum ions; Phosphatesilicate glasses; Raman spectroscopy