Benzil-azobenzene, eutectic

Figures 5a and 5b show the growth of benzil LlkT = 6). Figure 5a shows pure benzil and Fig. 5b shows the benzil-azobenzene eutectic. Both phases are present in Fig. 5b and both are bounded by low index faces, despite the diffusion processes involved. The growth here is quite anisotropic.

Fig. 5b. Benzil-azobenzene eutectic growing from the melt as in Fig. 5a (150 X).

A third compilation intended to be devoted to polymorphic materials is that of Kuhnert-Brandstatter (1971). The body of this book is an identification table for hot stage studies of pharmaceutical materials (see Sections 4.2 and 7.2), in which materials are arranged by increasing melting point, with eutectic data for mixtures with azobenzene and benzil. There is considerable descriptive detail on the melting behaviour and identification and description of polymorphic forms, albeit only microscopic determinations, for approximately 1000 pharmaceutically important... 

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