Structural transitions and unusual magnetic behavior in Mn-doped Bi_1−xLa_xFeO₃ perovskites Available to Purchase

The effect of Mn doping on crystal structure and magnetic behavior of the polar antiferromagnetic and antipolar weak ferromagnetic phases of the Bi_1−xLa_xFeO₃ system was investigated. Both reference compounds, Bi_0.87La_0.13FeO₃ (space group R3c, tilting scheme (a⁻a⁻a⁻)] and Bi_0.82La_0.18FeO₃ [space group Pnam, tilting scheme (a⁻a⁻c⁺)/(a⁻a⁻c⁻)], were shown to undergo the Mn doping induced structural phase transformation towards the average Imma (a⁻b⁰a⁻) symmetry. Magnetization measurements performed for the compounds with the close to maximal manganese concentration (y = 0.4) found complex temperature-dependent behavior that can be indicative of a spin-reorientation transition. Enhanced spontaneous magnetization characteristic of the Mn-enriched x = 0.13 and x = 0.18 samples at low temperature is consistent with a competitive character of the superexchange interactions peculiar to the Fe/Mn containing perovskite systems.