An NMR study of silicon coordination in Y–Si–Al–O–N glasses

Abstract

A series of seven Y–Si–Al–(O,N) glasses with constant Y: Si: Al ratio and increasing substitution of nitrogen for oxygen has been investigated by ²⁹Si NMR (MAS) spectroscopy. The spectra obtained are indicative of (i) nitrogen entering the glass network, and (ii) the coexistence of a variety of structural units. The data are discussed in terms of a structural model based on Si(O,N)₄ and Al(O,N)₄ tetrahedral units with a preference for Si-N bonding compared with Al-N bonding.