Enhanced dielectric, magnetic, and photocatalytic properties of sol-gel synthesized Eu-Cr codoped BiFeO3 nanoparticles

Abstract

A series of polycrystalline Eu-Cr co-doped BiFeO3 nanoparticles were synthesized using the sol–gel method. The obtained samples were characterized by employing the XRD, FTIR, FESEM, UV–vis, LCR meter, and SQUID techniques. XRD analysis confirmed rhombohedral phase formation for all samples, and the crystallite sizes decreased with higher Cr3+ doping concentrations. The stretching and bending vibrations of Fe-O bonds in FeO6 octahedra and the formation of perovskite nature were confirmed by the FTIR analysis. From microstructural studies, a decrease in crystallite size with increased doping concentration was observed, corroborating the XRD results. The magnetic studies revealed an enhanced magnetization, probably caused by the distorted cycloid spin structure of the codoped nanoparticles with size ≤62 nm. The lower value of the squareness ratio of the M-H loop indicated strong magnetostatic interaction between grains, which might have played a great role in the enhancement of the maximum magnetization of the doped samples. The dielectric constant and loss tangent were evaluated as a function of frequency at room temperature. The photocatalytic activities of all the samples were evaluated by measuring the degradation of RhB dye under sunlight irradiation. The highest photocatalytic degradation efficiency of 94% was achieved with the substitution of Cr3+ (3%) and Eu3+ (4%) ions in BiFeO3 nanoparticles.