Local states of iron ions in perovskite Bi0.815Y0.085La0.10FeO3

Bi_0.815Y_0.085La_0.10FeO₃ perovskite is studied by ⁵⁷Fe Mössbauer spectroscopy at 87, 295, and 670 K. The measured temperature of the magnetic phase transition (the Néel temperature) is T _N = 666 ± 5 K. It is found that substituting Y³⁺ ions for 0.085 at % Bi³⁺ in the Bi_0.9La_0.1FeO₃ perovskite destroys the spatially spin-modulated structure while the rhombohedral crystal structure is retained. Two structurally nonequivalent states of iron ions are found above the Neel temperature. Below the Neel temperature, there are four magnetically nonequivalent states of trivalent iron ions.