Study of Structural, Magnetic, Dielectric Properties and Estimation of Magnetoeletric Coupling of La, Mn co-doped Bi_1−xLa_xFe_0.97Mn_0.03O₃ Ceramics

La and Mn co-doped Bi_1−xLa_xFe_0.97Mn_0.03O₃ (BLFMOx, x = 0.05, 0.1, 0.2) ceramics were prepared by solid-state reaction method, and their structural, magnetic, dielectric and magnetocapacitance properties were studied. It was discovered that the co-substitution of La & Mn at sites of Bi & Fe suppressed impure phases which normally occur in BiFeO₃ synthesis. BLFMOx samples were calcinated, and well crystalline phases were acquired at a sintering temperature of 950 °C. X-rays diffraction patterns of the samples were recorded and investigated for the affirmation of crystal structure and determination of the lattice parameters. The normal grain size of the samples was observed to be between 1 and 2 μm. M–H graphs of BiFeO₃ and BLFMO_0.05 ceramics consist of straight-line, confirming antiferromagnetic nature of samples. Dielectric constant was diminished with increase in frequency for each composition. BLFMO_X ceramics showed negative magnetocapacitance and decrease in dielectric constant with magnetic field. Relative difference in dielectric constant initiated by external magnetic field might be approximated by ∆ε/ε = kM² for BLFMO_X, and here, magnetoelectric interaction (k) is negative.