Investigation of structural and magnetic properties of Tb–Ni-doped bismuth ferrite nanoparticles by auto-combustion method

The current work reports the synthesis of Bi1−x Tb x Fe1−x Ni x O3 (x = 0, 0.01, 0.03) using auto-combustion sol–gel method. XRD analysis reveals the formation of a rhombohedrally distorted perovskite structure to the R3c space group at room temperature. The crystallite size decreases from 46 to 15 nm with increasing dopants concentration. The presence of two strong peaks between 440 and 590 cm−1 attribute to bending and stretching of FeO bond, the characteristic of the octahedral FeO6 group in perovskite structure. The presence of irregular morphology is observed in the FE-SEM images. The occurrence of doublet in Mossbauer spectra of x = 0.03 sample indicates the superparamagnetic nature of the material. From VSM analysis, the coercivity of x = 0.03 sample is found to be zero, also supporting the superparamagnetic nature of this sample.