Structure, magnetic, and electrical properties of bismuth niobates doped with d-elements: XIII. State of iron atoms in the Bi3Nb1–xFexO7–δ solid solutions

Abstract

From the data of magnetochemical study and ESR spectra of samples of the Bi₃Nb_1–xFe_xO_7–δ (х ≤ 0.06) solid solutions iron atoms in the solid solutions of cubic modification of bismuth niobate were found to be located as Fe(III) monomers and exchange-bonded Fe(III)–O–Fe(III) dimers with anti- and ferromagnetic exchange types. The exchange parameters and the distribution of monomers and dimers over the solid solution were calculated as functions of the paramagnetic atom fraction.