Abstract
Isothermal growth of β-Si 3N 4 crystals dispersed in rare-earth (RE = Y, Gd, Nd and La) oxynitride melts (RE-Mg-Si-O-N) was studied during heat treatment at 1773 K under 0.9 MPa of nitrogen pressure for 64 to 512 min. The microstructure of β-Si 3N 4 crystals was characterized by electron microscopy. It is found that the rate of α-β transformation increases with decreasing ionic radius of the rare-earth element. Likewise, the radii of rare-earth elements make significant differences in the morphology and mean aspect ratio of β-Si 3N 4. Especially, the aspect ratio of β-Si 3N 4 crystals with the additive of La 2O 3 was found to be much larger than that in oxynitride melts with additives of others.
Original language | English |
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Pages (from-to) | 719-722 |
Number of pages | 4 |
Journal | Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals |
Volume | 69 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 1 2005 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry