Features of Powder Synthesis in ZnO–SnO2 System

Abstract—The effect of the anionic composition of zinc salts upon interaction with tin(IV) chloride on the production of zinc orthostannate by the sol-gel method under the influence of microwave radiation is studied. It is determined that the temperature at which the synthesis of zinc orthostannate begins depends on the type of zinc-containing salt used and is 800°C for zinc sulfate and zinc acetate and 900°C for zinc nitrate. It is revealed that, when using zinc chloride, the formation of tetra-ammine zinc chloride occurs, which decomposes during roasting and does not allow synthesizing the target product. When synthesizing complex oxides from simple ones, the difference in the diffusion coefficients of Zn2+ and Sn4+ cations leads not only to the Kirkendall and Frenkel effects but also to a deviation from stoichiometry (γ nonstoichiometry). From a mixture of simple oxides of stoichiometric composition, a solid solution of zinc oxide is formed in the stoichiometric compound 2ZnO·SnO2 and a phase consisting of tin oxide or enriched in it.