The influence of rare earth doping on the structure, magnetic properties, and application of LaFeO3 nanoparticles

Abstract The perovskites La 1-x R x FeO 3 (x = 0.0 and 0.1; M: Sm 3+ and Gd 3+ ) were synthesized using the citrate method. The X-ray diffraction reveals that the samples were prepared in a single phase orthorhombic structure with an average crystallite size of 42–46 nm. The field emission scanning electron microscope studied the morphology of La 1-x R x FeO 3 perovskites and indicated the presence of pores on the surface of nanoparticles. The magnetization of LaFeO 3 has a strong effect on the doping La 3 + site by Sm 3+ and Gd 3+ ions. The saturation magnetization increased from 0.57 emu/g for LaFeO 3 to 1.27 emu/g for La 0.90 Sm 0.10 FeO 3 ; while, the remnant magnetization decreased from 0.111 emu/g for LaFeO 3 to 0.026 emu/g for La 0.90 Gd 0.10 FeO 3 . The samples have antiferromagnetic with weak ferromagnetic properties. The presence of Sm 3+ and Gd 3+ ions at the expense of La 3+ leads to tilting the FeO 6 octahedron and increasing the canting angle between Fe 3+ –O 2 –Fe 3+ . The La 1-x R x FeO 3 nanoparticles have a good removal efficiency for removing highly toxic Cr 6+ ions from water using a low-cost and eco-friendly adsorption method. The removal efficiency of La 0.90 Gd 0.10 FeO 3 is 88.2% at pH 5. The Langmuir model is the best fit model with the experimental data.