Influence of Sr and Mn co-doping on the structural, optical, dielectric, multiferroic properties and band gap tuning in bismuth ferrite ceramics.

Solid state reaction was employed to synthesize the Bi_1−xSr_xFe_1−xMn_xO₃ (x = 0.05, 0.10, 0.20, 0.25) ceramic materials. XRD reveals the single-phase rhombohedral structure with R3c space group of the prepared materials. The FTIR spectra have been used to calculate the Fe–O bond length. The UV–Visible diffuse reflectance spectra was used for the calculations of the band gaps, which are found to decrease from 2.02 to 1.83 eV on increasing the Sr and Mn co-doping in BFO. P-E loops were recorded for the samples to determine ferroelectric nature at various applied fields. M-H hysteresis loops show a significant change in remnant magnetization (M_r), saturated magnetization (M_s) and coercive field, (H_c) with Sr–Mn substitution in BiFeO₃. From FESEM images revealed agglomerated particles in the samples investigated and an increase in grain size is observed with increase in co-doping in BiFeO₃. Out of all the prepared samples, Bi_0.90Sr_0.10Fe_0.90Mn_0.10O₃ with modified values of multiferroic parameters among the Bi_1−xSr_xFe_1−xMn_xO₃ (x = 0.05, 0.10, 0.20, 0.25) may be useful as a promising multiferroic material for applications of actuators, sensors and multistate memory devices. [ABSTRACT FROM AUTHOR]