Spinel crystallography

Figure 48 The structure of fi-alumina shown as a packing of spinel layers. The alkali metal ions, which are not shown, are to be found in the empty positions between the spinel sheets (Reproduced by permission from Crystallography and Crystal Chemistry of Materials with Layered Structures , ed. F. Levy, Reidel, Dordrecht, Holland, 1976, p. 127)...

Use Crystallography synthetic spinel is used as a refractory and in electronic applications. 

To trace the relationship between the valence transition and the evolution of crystal structure, electron diffraction patterns were recorded in situ at different temperatures, as shown in Figure 4.5. The crystal structure is Mn02 (with rutile structure), and no visible change in crystallography is observed up to 400 C. From 400 to 450°C, the crystal structure experiences a rapid change from rutile to spinel, and the final phase at 500°C is identified to be dominated by Mn304, with... 

The crystallography, stoichiometry, and typical properties of MA spinel will be described followed by a discussion of preparation methods of spinel powders and aggregates. The production, microstructures, and properties of several of... 

---