The solubility of α-silicon nitride into RE2O3 (RE = Y, Gd, Nd and La) -MgO-SiO2 melts have been examined systematically. The effect of nitrogen content on the Vickers hardness of RE-Mg-Si-O-N oxynitride glasses have been examined. The dissolution reaction of α-silicon nitride into melts have achieved equilibrium about 6 h holding at 1773 K. The content of saturated nitrogen was 4.8-5.8 at%, depending on the ionic radius of adding rare-earth elements. A marked change was observed in the order of ionic radius from La to Y. The Vickers hardness of RE-Mg-Si-O-N oxynitride glasses increased with increasing the content of nitrogen. The results from X-ray photo-electron spectroscopy of oxynitride glasses revealed the existence of Si ≡ N bonds. These results suggest that the substitution of nitrogen for oxygen may lead to the increase of cross-linking produces a more rigid glass network.
|ジャーナル||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|出版ステータス||出版済み - 1 1 2004|
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