Two-step combustion synthesis of single-phase mesoporous ScFeO3 with bixbyite structure and magnetically soft behavior

Abstract

In this paper, we consider the possibility of obtaining cubic bixbyite-type scandium ferrite in the form of phase-pure nanopowders. The samples were obtained by solution combustion method with either lack or excess of fuel and represented an X-ray amorphous phase according to the X-ray diffraction (XRD) results. To obtain cubic scandium ferrite, the samples were subjected to heat treatment at 700 °C, determined using DTA/TGA. The XRD data analysis confirmed the formation of cubic scandium ferrite with an average crystallite size of ∼20 nm for the sample obtained with a lack of fuel and 13 nm with an excess of fuel. According to the low-temperature nitrogen adsorption-desorption technique, the specific surface of the mesoporous samples decreased after annealing from 39.7 m2/g to 20.5 m2/g for the sample obtained with a lack of fuel and from 82.7 m2/g to 34 m2/g for the sample obtained with excess fuel. Scanning electronic microscopy (SEM) results demonstrated the foam-like morphology of nanopowders and no significant changes in their microstructure after heat treatment. The magnetic properties of powders that have undergone heat treatment have been studied. Narrow M-H hysteresis loops and low values of the coercive force indicate ferromagnetic behavior of the synthesized nanoparticles, which is supported by low values of the coercive force (Hc = 345 Oe and 769 Oe), remanent magnetization (Mr = 0.65 emu/g and 0.26 emu /g) and saturation magnetization (Ms = 1.69 emu/g and 0.26 emu/g) for lack and excess of fuel, respectively. The obtained materials are classified as magnetically soft and can potentially be used in the creation of transformers, magnetic screens, magnetic memory systems, radio engineering, and computer technology.