Chemical synthesis zinc ferrite

This chapter presents detailed and thorough studies of chemical synthesis in three quite different chemical systems zinc ferrite, intermetallic, and metal oxide. In addition to different reaction types (oxide-oxide, metal-metal, and metal oxide), the systems have quite different heats of reaction. The oxide-oxide system has no heat of reaction, while the intermetallic has a significant, but modest, heat of reaction. The metal oxide system has a very large heat of reaction. The various observations appear to be consistent with the proposed conceptual models involving configuration, activation, mixing, and heating required to describe the mechanisms of shock-induced solid state chemistry. 

Fig. 8.1. Shock-induced solid state chemical synthesis of a zinc ferrite has been studied over a wide range of temperature and pressure. The figure shows the location of conditions for which the reaction has been studied.

For the synthesis of zinc ferrite (ZnFe204) of stoichiometric composition CFD and HPS samples were mixed in an appropriate ratio. From the chemical analysis the Fe/Zn molar ratio of the mixture was 2.18. To override the problem of the coohng effect of volatiles on the plasma (mentioned above), prior to mixing HPS sample was preheated at 300 °C to reduce its volatile (H2O) content. Conditions of the plasma treatments can be seen in Table 3. In order to improve heat transport between the hot gases... 

These results demonstrate tliat shock-wave synthesis is a novel metliod to prepare nanosized materials with some unique physical and chemical properties. In the light of the experimental results, nanosized zinc ferrite and nickel ferrite synthesized by shock-wave treatment may Iiave potential applications as magnetic materials and photocatalysts. 

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