Magnetic, ferroelectric, and magnetocapacitive properties of sonochemically synthesized Sc-doped BiFeO₃ nanoparticles

Abstract

We report the synthesis of undoped and Sc³⁺-doped BiFeO₃ nanoparticles using the sonochemical technique. X-ray diffraction reveals that all samples are single phase with no impurities detected. EDX analysis was done to confirm the extent of Sc³⁺ doping in the samples. The size and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM). XPS studies were done to check the presence of Fe²⁺ ions in the samples. The BiFeO₃ nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M–H relationship reported for bulk BiFeO₃. The substitution of Sc ions for Bi enhances the ferromagnetic as well as ferroelectric properties of this system, which is mainly attributed to the antiferromagnetic core and ferromagnetic surface of the nanoparticles, together with the mild structural distortion. Temperature and field dependence of magnetization curves reveal the frustrated magnetic behavior of this system. The leakage current is considerably reduced, and electric polarization increases significantly in the case of BiFe_0.95Sc_0.05O₃ nanoparticles. Magnetoelectric coupling was observed in the BiFe_0.95Sc_0.05O₃ sample. Thus, it can be inferred that Sc³⁺-doped BiFeO₃ nanoparticles show promise as good multiferroic materials.