Hematite (a-Fe2O3) and eskolaite(Cr2O3) are typicalexamples of isostructural oxides with non-linear change of the latticeparameters in their solid solutions. This series was synthesized andcharacterized by X-ray and neutron powder diffraction, and Mossbauer andelectronic spectroscopies. A region of the d-d electron transition of Fe(III)ions in near IR region (about 1000 nm) were found to be suitable for the solidsolution characterization, because the transition does not suffer from strongoverlaps of Fe(III) and Cr(III) transitions in electronic spectra in the Visspectral range. Lattice parameters, verified by the comparison to data availablein literature, showed that in several cases in the last decade solids ofquestionable quality were obtained and discussed in the hematite-eskolaitesystem. Neither X-ray nor neutron diffraction indicated cation ordering,hypothesized in two reports in 1990's. Magnetic structure of the solid solutionat 0 < x < 0.6, where x = Cr/(Cr + Fe), is similar to that of hematite,but a different, yet unidentified magnetic ordering involving Fe(III) ions isestablished in solid solution x = 0.8 below its Neel temperature (about 150 K).
