Nanostructured YbMn1−хFeхO3 and its physical properties

The present study investigates the concentration dependence of physical properties and structural parameters of YbMn1−хFeхO3 (YbMF) compositions, which were nanostructured using the mechanical activation method at a pressure of 1 GPa. Using X-ray diffraction, the dependence of the unit cell parameters of the H-hexagonal (P63cm) and O-orthorhombic (Pnma) phases on the Fe3+ dopant concentration was studied. It was found for the first time that a morphotropic region (MR) was formed in YbMF in the concentration range x = 0.6–0.8, characterized by the coexistence of H and O-phases. At the point х = 0.5, the minimum values of all bond lengths of the H-phase were observed, while at х = 0.8, the bond length minimum of the YbO8 dodecahedra of the O-phase was observed. The tilt θ° and rotation φ° angles of oxygen octahedra MnO6/FeO6 of the O-phase also vary with the Fe3+ concentration in the range of (19.354–19.754)° and (12.648–12.677)°, respectively. Using the complex impedance method Z* = Z′(ω) − j·Z″ (ω), the study showed that the relaxation character was non-Debye. Theoretical and experimental curves were obtained for each YbMF composition at different temperatures, along with the corresponding equivalent circuits. The study also investigated the parameters of the stochastic magnetic domain structure using the random magnetic anisotropy model. It was found that in the region of solid solutions of YbMF, the values of Hc and Mr have maxima at x = 0.5, and the highest value of Hc, equal to 452 Oe, is inside the MR.