Glass-forming ability and structure of ZnO-MoO3-P2O5 glasses

• Published in: Journal of non-crystalline solids 2010-10, Vol.356 (44-49), p.2509-2516
• Main Authors: SUBCIK, Jiří, KOUDELKA, Ladislav, MOSNER, Petr, MONTAGNE, Lionel, TRICOT, Gregory, DELEVOYE, Laurent, GREGORA, Ivan
• Format: Article
• Language: English
• Subjects: Bonding; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Disordered solids; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Glass; Glass transitions; Glasses; Glasses (including metallic glasses); Magnetic resonances and relaxations in condensed matter, mössbauer effect; Materials science; Molybdates; Molybdenum; NMR spectroscopy; Nuclear magnetic resonance and relaxation; Oxygen atoms; Physics; Specific materials; Specific phase transitions; Spectra; Structure of solids and liquids; crystallography; Ternary systems; Zinc oxide
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2010.02.013

Glasses in the ternary system ZnO-MoO3-P2O5 were studied. The determined glass-forming region is very large and covers the concentration range from pure P2O5 up to the glass compositions with only 20mol% P2O5 and 70mol% MoO3. Structure of these glasses was analyzed in four compositional series containing 50mol% of P2O5 in the series of (50a degree t)ZnO-tMoO3-50P2O5, 10mol% of ZnO in the series of 10ZnO-yMoO3-(90a degree y)P2O5 and 20mol% MoO3 in the series of zZnO-20MoO3-(80a degree z)P2O5. The fourth series contained equimolar ratio of ZnO/P2O5 and its composition was (100a degree x)[0.5ZnO-0.5P2O5]-xMoO3. Basic structural units in this ternary system were identified in specific compositional regions using Raman and 31P MAS NMR spectroscopy. By the deconvolution of NMR spectra compositional dependences of Q n units were obtained. The presence of isolated MoO6 octahedra was detected in the glass with 70mol% P2O5. In the MoO3-rich and ZnO-rich region clustering of MoO6 octahedra was observed, but the formation of Mo-O-Mo bonds was found already in the P2O5-rich glasses containing 60mol% P2O5. Molybdate structural units are preferentially bonded to non-bridging oxygen atoms of PO4 units and P-O-Mo bonds do not tend to replace P-O-P bonds.