Phase equilibria and crystal structure of the solid solution LaFe1−xNixO3−δ (0 ≤ x ≤ 1)

Phase equilibria in the LaFeO3–“LaNiO3” were studied at 1100 °C in air. The samples were synthesized by standard ceramic and/or solution route via nitrate or citrate precursors. According to the results of XRD it was found that the homogeneity ranges of LaFe1−xNixO3−δ solid solution lay within 0.0 ≤ x ≤ 0.4 (sp.gr. Pbnm) and 0.6 ≤ x ≤ 0.8 (sp.gr. R3¯c). The structural parameters (bond lengths, atom coordinates) for the single-phase samples were refined using Rietveld analysis. The unit cell parameters versus LaFe1−xNixO3−δ composition are presented.