STRUCTURAL CHARACTERIZATION OF SI-AL-O-N GLASSES

Glasses in the SiO2-rich portion of the SiO2-Si3N4-Al2O3-AlN system ha ve been prepared by a 'pressureless' sintering method and glass compos itions have been determined by electron microprobe analysis. The glass -forming region agrees well with that determined in previous studies. The glass structures have been studied via Si-29 and Al-27 NMR and by IR spectroscopy. IV-, V- and VI-coordinated AlOn groups are present fo r all compositions. The nitrogen is incorporated in Si(O3N) tetrahedra l units. (C) 1998 Elsevier Science B.V.