Improved magnetic and electrical properties of Bi_1−xCa_xFeO₃ multiferroic nanomaterials

This paper investigates the structural, morphological, magnetic, and electrical characteristics of sol–gel auto-combustion synthesized Bi_1−xCa_xFe₂O₃ (x = 0.00, 0.05, 0.1, 0.15, 0.2, and 0.25) multiferroics. Characterization of the synthesized samples was conducted using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), and electrical properties by Impedance Analyser. The materials exhibit a rhombohedral structure within the R3c space group. FESEM experiments revealed the nanocrystalline nature of the prepared materials. The FTIR spectra display Fe–O bond vibrations at approximately 450–465 and 560–582 cm⁻¹. Magnetic measurements indicate an enhancement in saturation magnetization for doped samples, with Ca-doped BFO nanoparticles showing a saturation magnetization ranging from 1.45 emu/g to 2.49 emu/g at a 20kOe applied magnetic field. The observed increase in the diameters of the semicircles and their higher frequency shifting in the cole-cole plot across the 10 Hz^–1 MHz frequency range suggests a rise in granularity and its limits.