Cordierite nucleation

Further investigations on the kinetics of cordierite nucleation revealed that the elastic strain term (AGg) in Eq. 1-1, could also be of significance in surface nucleation. In a specialized experiment,... 

The importance of transparent glass-ceramics doped by Cr as potential new materials for luminescent solar concentrators and tunable lasers is considerable It has been shown that Cr(III) exhibits exceptionally high quantum efficiency of luminescence in these materials as compared to glasses of the same compositions . Cr is also used as a probe for nucleation of and crystallization of cordierite into glass-ceramics . ... 

Findings from the theories of nucleation have also contributed to the optimization of these comprehensive experimental investigations. As a result, glass-ceramics with improved properties have been produced, specifically glass-ceramics with specific solid-solution limits like j3-spodumene and stuffed P-quartz or with stoichiometric compositions like cordierite and lithium disilicate. Initial results for the successfU application of the theory of nucleation to multicomponent glass-ceramics with a nonstoichiometric composition were achieved with mica and anosovite glass-ceramics. 

This crystal growth mechanism is linked to surface nucleation. The success-fill application of the mechanisms of surface nucleation and crystallization in the development of cordierite (Semar and Pannhorst, 1991), apatite-wollastonite (Kokubo 1991), and leucite glass-ceramics (Holand et al., 1995a) has already been mentioned in Section 1.4. 

Following the initiation of surface nucleation, the crystal growth mechanism demonstrated at least three extraordinary features in cordierite (Zanotto 1994 Schmelzer et al., 1995 Donald 1995) as well as leucite glass-ceramics (Holand et al., 1995 a,b). 

Another example lies in the development of cordierite, a desirable and stable refractory, low-thermal-expansion crystal in the Si02—AI2O3—MgO system. Here a reaction occurs between metastable phases, spinel, a-quartz, and the nucleating titanate (pseudobrookite structure) to produce cordierite and rutile as follows ... 

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