Investigations on structural, dielectric and multiferroic properties of Bi₂FeNiO₆ double perovskite synthesized using sol-gel modified combustion technique

This paper reports the structural, dielectric, electrical, and multiferroic properties of Bi₂FeNiO₆ (BFNO) double perovskite synthesised using a sol-gel modified combustion technique. Its calcination temperature, 873 K, was determined using the mass variation in the TGA curve. Structural characterisation was conducted with the X-ray diffraction technique and the perovskite was found to adopt a cubic structure with space group Fm \(\bar{3}\) $\overline{3}$ m (#225). Synchrotron-based powder angle dispersive X-ray diffraction (ADXRD) measurements were carried out to analyze the structural stability with temperature variation (RT-773 K). SEM studies revealed nearly cubic nanostructures with an average grain size of ~54 nm. EDS and XPS studies confirm the stoichiometric and electrical neutrality of the compound, respectively. The ε vs T curve shows the ferroelectric Curie temperature to be around 732 K, corroborating an exothermic peak observed in the DSC curve around the same temperature. The M-H curve and PE loop show the coexistence of ferroelectric and ferromagnetic properties in the as-prepared Bi₂FeNiO₆ at room temperature.