Phase transformation and the mechanism of combustion synthesis of ZnFe2O4 ferrite powders

The reaction mechanism of combustion synthesis of zinc ferrite, which belongs to the complex oxide combustion reaction was investigated using a combustion front quenching method (CFQM). Phase transformation and microstructural evolution of the quenched samples were observed by XRD, SEM, and Mِssbauer spectroscopy. The results showed that the combustion proceeded by a dissolution-precipitation mechanism, viz the iron was burned to form Fe2O3 in an oxygen atmosphere and melting of the Fe2O3 led to the dissolving of the ZnO particles, then ZnFe2O4 precipitated out. In addition, a model of the mechanism was drawn.