A Review to the Effects of Cations Replacement on the Properties of Combined Spinels Based on Cobalt, Zinc and Magnesium

Recently, CoAl2O4, MgAl2O4 and ZnAl2O4 have been considered as the most widely used spinel structures in industrial applications as catalysts, basic catalysts and pigments especially at nano scale. Studies have shown that the composites including the combination of different types of spinels have more desirable properties in comparison to the absolute spinels. In this research review paper, the structures, properties, advantages and disadvantages of the neat spinels have been studied. Moreover, the effect of cations replacement, M=Zn, Mg, Mn, Ba, Sr, in CoxM1-xAl2O4 structures has been evaluated as one of the novel methods of spinel improvement. The results show that these replacements strongly improve the characteristics of the new combined spinels structures. For example; Increasing Zn cation results in reducing the toxicity and cobalt aluminate pigment production costs and leads to control the phenomenon of ion exchange between tetrahedral and octahedral position.