Preparation and Properties of Yttrium‐Silicon‐Aluminum Oxynitride Glasses

Abstract

Glasses containing up to 7 at.% nitrogen were prepared in the system Y‐Si‐Al‐O‐N. The glass transition temperature, hardness, and relative fracture toughness increase and the thermal expansion coefficient decreases with increasing nitrogen content. Weight losses after 350 h in 95°C distilled water are not simply related to nitrogen content, but for some compositions they are half that reported for fused silica. The electrical conductivity at 548°C and 10 kHz is 7.8×10 −10 (Ω·cm) −1 for one composition. Fourier transform ir spectroscopic analysis indicates the presence of Si‐N bonds in the glasses. The data suggest that nitrogen substitutes for oxygen in the glass network to produce a more highly cross‐linked structure.