Hyperfine Interactions of 57Fe Nuclei in ScCo1–xFexO3 (x = 0.05, 0.4) Substituted Cobaltites

The Mössbauer study of 57Fe nuclei in Sc1–yCo1–xFexO3–3/2y (x = 0.05, 0.4; y = 0.1, 0.2) cobaltites has been reported. Mössbauer spectra, as well as calculations of the parameters of the electric field gradient tensor, have shown that Fe3+ cations not only occupy characteristic for them positions with octahedral oxygen coordination, but also partially substitute Sc3+ cations in ScOn polyhedra with a large coordination number (n = 8–12). The character of distribution of iron cations over two positions depends on the composition of studied cobaltites. In contrast to Co3+ cations, Fe3+ cations in both positions are stabilized in a highspin state (S = 5/2). The analysis of the magnetic hyperfine structure of 57Fe spectra measured at T < TN has shown that magnetically ordered iron-rich microclusters can be formed in the octahedral sublattice of the Sc0.9Co0.6Fe0.4O2.85 and Sc0.8Co0.6Fe0.4O2.7 cobaltites. The most fraction of iron in Sc0.9Co0.9557Fe0.05O2.85 remains in the paramagnetic state down to the lowest temperatures.