Oxygen/nitrogen ordering in lanthanum new phase (La3Si8N11O4)

Koroglu A., Thompson D., Apperley D., Harris R.

JOURNAL OF SOLID STATE CHEMISTRY, vol.177, no.7, pp.2530-2533, 2004 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 177 Issue: 7
  • Publication Date: 2004
  • Doi Number: 10.1016/j.jssc.2004.03.023
  • Journal Name: JOURNAL OF SOLID STATE CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2530-2533
  • Keywords: MAS NMR, sialons, lanthanum new phase, NUCLEAR-MAGNETIC-RESONANCE, ANGLE-SPINNING NMR, O-N SYSTEM, SILICON OXYNITRIDE, NITROGEN MELILITE, MAS-NMR, N-15, AL-27, SI-29, CERAMICS
  • Ondokuz Mayıs University Affiliated: No

Abstract

High-resolution O-17 NMR spectra have been collected for crystalline samples of lanthanum new phase, La3Si8N11O4. In conjunction with previously published Si-29 and N-15 spectra obtained for this phase, and in the light of the high-quality crystal structure data reported recently, a more detailed interpretation of the NMR spectra is presented than was possible in previous studies. The non-bridging oxygens in the structure are responsible for the single sharp peak seen in the 170 spectrum at 188 ppm; the remaining oxygens, occupying bridging sites shared with nitrogen, show up only weakly on the 170 spectrum as a broad diffuse band centered around zero ppm. The peak at -57.3 ppm on the Si-29 spectrum is believed to correspond to an overlap of [SiN4] and [SiON3] environments, with the -68.2 ppm peak corresponding to an [SiO2N2] environment. (C) 2004 Published by Elsevier Inc.