Magnetic properties and magnetism simulation of SmFe 0.5 Cr 0.5 O 3 nanoparticles prepared by sol-gel method

This study reported the synthesis process of SmFe 0.5 Cr 0.5 O 3 by the sol-gel method, and its structure, hyperfine parameters and magnetic properties are also studied. X-ray diffraction (XRD) revealed the Pbnm(62) spatial group characteristics of the nanoscale size and orthogonally distorted perovskite structure of the samples. The Mössbauer spectrum shows the characteristics of trivalent hexacoordinated high spin ( s = 5/2) of 57 Fe in the sample and the distorted octahedron symmetric structure environment of triangle or quadrilateral. Magnetization data and Mössbauer spectra record magnetic phase transition at about 250 K ( T N = 250 K). Under the Néel temperature, the system exhibits a frustrated spin glass state. Monte Carlo simulation of magnetization curves based on 3D Heisenberg model modified by Dzyaloshinskii-Moriya (DM) interaction results in the main exchange constants in the sample ( J Fe-Cr /k B = 16.04 K) and magnetic phase transition temperature (~250 K). To explore the magnetic properties and mechanism of SFCO nanoparticles. On the one hand, the temperature dependence of sample magnetization (FC, ZFC-T, 200Oe) and isothermal magnetization (M-H, 5 K) curves show that SFCO is a frustrated system with T N ~250K (Figure (a), (b), (c), (d) and (e)). On the other hand, the variable temperature Mössbauer spectra (RT, 250 K, 210 K, 170 K, 100 K) strongly demonstrate the antiferromagnetic transition at about 250K(figure (f)). In addition, the three-dimensional Heisenberg model modified by Dzyaloshinskii- Moriya (DM) was used to simulate its magnetic properties by Monte Carlo method, as shown in Figs. (g), (h) and (i), which showed excellent fitting results ( J Fe-Cr / k B = 16.04 K), and further supported the existence of magnetic phase transition at about 250 K.