Abstract
The mineral species of co-precipitated products from a mixed solution of ferric and copper sulfates (Fe/Cu=2.0) at 20-200°C were discriminated by means of X-ray diffraction, and the crystallographic properties of copper ferrite contained in it were investigated in relation to cubic-tetragonal transformation.
The mineral phase of the precipitates, owing to X-ray diffraction, was one of the four states of amorphous, CuO, the mixture of CuO and Cu-ferrite and the mixture of CuO, Cu-ferrite and a-hematite depending on the temperature and pH.
The crystal systems of obtained Cu-ferrites were whole cubic regardless of aging conditions. When they were treated by heating (740°C), the crystal systems of Cu-ferrites formed in neutral and slightly alkaline solutions (pH 6-11) changed to tetragonal, but those in strongly high alkaline solutions remained unchanged. From the chemical analysis or measurements of lattice constant on Cu ferrite containing sodium by dry method, it was supposed that the Cu-ferrite obtained in strongly alkaline solution contains sodium ion in cubic lattice and it prevents the cubic-tetragonal transformation of Cu-ferrite.
