X-ray diffraction investigation of phase stability in the Co-Cr-O and the Fe-Co-Cr-O systems in air at 1323Â K

Incorporation of Fe cations in the Co-Cr spinel was observed to expand the spinel lattice. Qualitative phase analyses of the Fe-Cr-Co oxide mixtures indicate that connecting the phase fields in the Fe-Co-O and Cr-Co-O system gives a fair prediction of the phase fields in the Fe-Cr-Co-O system at 1323 K (in air).