Influence of oxygen pressure on combustion synthesis of zinc ferrite powders

The influence of the oxygen pressure on the phase composition, microstructural evolution of the combustion products during the combustion synthesis of zinc ferrite through iron, iron oxide, and zinc oxide powders was discussed. The results show that with the increase of oxygen pressure, combustion temperature and combustion wave velocity increase. Single spinel-phase zinc ferrite can be obtained when the oxygen pressure is 1.0 MPa and a non-stoichiometric composition, Fe1−xO or Fe1−zO is formed when the oxygen pressure is below 1.0 MPa or above 1.5 MPa. Moreover, an analysis of the dependence of the degree of conversion to ferrite, η, on the oxygen pressure has also been made. For a given porosity and combustion temperature, the degree of conversion increases with the oxygen pressure increasing and for any given porosity and degree of conversion, higher pressure is required at higher temperature.