Electrochemical determination of thermodynamic properties and x-ray diffraction investigation of the Fe3O4-ZnFe2O4 system.
Metall Trans B 1986 Sep; 17(3):515-521
The Bureau of Mines investigated the thermodynamic properties of the Fe3O4-ZnFe2O4 solid solutions. Activities of Fe3O4 (magnetite) in solid solutions were determined with high-temperature electromotive force (EMF) cells using stabilized ZrO2 (zirconia) as the solid electrolyte. Potential measurements were obtained from the cell Pt, Fe3O4, Fe2O3 || ZrO2 || Fe2O3, (Fe3O4)x(ZnFe2O4)1-x, Pt with the overall cell reaction Fe3O4 (pure solid) = Fe3O4 (in solid solution). The activity of Fe3O4 in solid solutions coexisting with Fe2O3 (hematite) exhibits a positive deviation from ideal solution behavior for the entire system. Equilibrium oxygen pressures for zinc oxyferrite solid solutions coexisting with Fe2O3 were calculated from the potential measurements. Partial and integral molar properties were derived for the Fe3O4-ZnFe2O4 system. Lattice parameter measurements of the Fe3O4-ZnFe2O4 solid solutions show a positive deviation from Vegard's law.
Metallurgical-processes; Mineral-processing; Chemical-reactions; Metal-compounds; Metallic-compounds; Magnesium-compounds; Thermodynamic-reactions; Iron-compounds
OP; Journal Article
Metallurgical Transactions. B. Process Metallurgy