Si-Al-O-N system

Redington Keely W, Redington M, Hampshire S (2000) Liquid Formation in the Y-Si-Al-O-N System. In Hampshire S, Pomeroy MJ (eds) Nitrides and Oxinitrides. Mater Sci Forum 325-326. Trans Tech Publications Ltd, Switzerland, p 237... 

Many studies of crystallisation of oxynitride glasses have concentrated on the Y-Si-Al-O-N system. Thompson (1989) outlined the various crystalline phases that exist in this system as shown in the Janecke prism in Fig. 21.2. 

Crystallisation to form composites in the Ln-Si-O-N and Ln-Si-Al-O-N systems has been reported. The disilicate, metasilicate, N-apatite and N-wollastonite phases found in the Y-Si-O-N system (see Fig. 21.2) also exist in the Ln-Si-O-N systems (Leng-Ward and Lewis, 1990 Mandal etal., 1992a Sun etal., 1995 Liddell et al., 1998). 

A new phase, SiAl4N402, has been characterized in the Si-Al-O-N system. It is believed to be a thermolysis product of the recently described j8 -Si3N4. ... 

The extent of the glass forming regions in various M-Si-Al-O-N systems (M = Mg, Y, Ca, etc.) has been studied previously and represented using the Janecke prism with compositions... 

This phase is one of the best examples of a nitrogen glass ceramic, and is also the best documented as regards composition and structure. It occurs at compositions of the type Ln3Si3Al30i2N2, and even though it has been prepared in the Y—Si—Al—O—N system, it is much more readily prepared in rare earth systems of low atomic number (typically La, Ce, and Nd). The structure is well established [59] Figure 5.23 shows the... 

Figure 7. Janecke s triangular prism for the Y-Si-Al-O-N system showing all known phases [24]...

Aluminium nitride polytypoids are phases in the Si-Al-O-N system with constanct (Si+Al) (0+N) ratio, whose structures can be classified by ramsdell... 

Fig. 8. Outline representation of the Y-Si-Al-O-N system. Glass-forming region within the yttrium-sialon triangular prism on cooling from 1700°C (Drew et al. 1981).

In rare-earth-Si-Al-O-N systems, the R2Si303N4 melilites are the highest nitrogen-containing compounds, apart from a-sialons, and they are characterized by a high melting point 1900 C for Y2Si303N4 (Jack 1986). 

---