SiAlON B-Phase Glass-Ceramic Microstructures
This paper is focussed on the development of microstructure during crystallisation heat treatment of B-phase parent glasses with composition (e/o) 35R:45Si:20Al:83O:17N, where R = Er, Yb, Y or a mixture of Y and Yb. Extensive high resolution analytical transmission electron microscopy has shown that the lenticular B-phase crystals take up a substantial range of composition. The element R is always clearly anti-correlated with the Si, and a larger R3+ cation radius moves the composition range to lower R contents. It is suggested that a locally increased density in the bi-dimensional network of randomly oriented (Si,Al)(O,N)4 tetrahedra is associated with an increased density of vacancies in the R3+ cation lattice.
Katsutoshi Komeya, Yi-Bing Cheng, Junichi Tatami and Mamoru Mitomo
L.K.L. Falk et al., "SiAlON B-Phase Glass-Ceramic Microstructures", Key Engineering Materials, Vol. 403, pp. 103-106, 2009