Abstract
The development of microstructure during crystallisation of a glass with composition Y15.2Si14.7Al8.7O54.1N7.4 has been studied by analytical and high resolution transmission electron microscopy. Crystal nucleation at temperatures in the range 965-1050°C occurs by the heterogeneous nucleation of lenticular-shaped yttrium, silicon and aluminium containing crystals on silicon-rich clusters that formed during glass preparation. The lenticular crystals have a wide range of composition after heat treatment at 1050°C; the yttrium cation percentage varies around that of the expected B-phase composition Y2SiAlO5N but the aluminium content is lower and the silicon content generally significantly higher than that. The crystals display the hexagonal crystal structure of B-phase, although the results from EDX analysis imply that the atomic arrangement of the lattice is not the previously proposed B-phase structure. Crystal growth during prolonged heat treatment at 1050°C occurs to a significant extent by coalescence.
| Original language | English |
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| Pages (from-to) | 6-19 |
| Number of pages | 14 |
| Journal | Journal of Non-Crystalline Solids |
| Volume | 270 |
| Issue number | 1-3 |
| DOIs | |
| Publication status | Published - 11 May 2000 |