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La 0. 8 Sr 0. 2 Fe 1 − x Mn x O 3 (x = 0. 0 , 0.1, 0.3 and 0.5) series samples were prepared by sol–gel method and characterized by powder X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Mössbauer spectroscopy. The effects of Mn doping on the microstructure, morphology and electronic structure of La–Sr ferrite were investigated. The XRD results show that all samples are single phase and have orthorhombic structures with Pbnm space group. The surface morphology and composition of chemical elements of the samples were analyzed by SEM and EDS, and the experimental values were consistent with the expected values. The sample was tested by 5 7 Fe Mössbauer spectroscopy at room temperature, and the results showed that the percentage of doublet increased gradually with the increase of Mn ion doping ratio, and at x = 0. 5 , all the sextet disappeared and only the doublet existed. According to the analysis, it can be seen that the prepared series of samples underwent a transition from antiferromagnetic to paramagnetic. La0.8Sr0.2Fe1–xMnxO3 (x = 0.0, 0.1, 0.3 and 0.5) series samples were prepared by sol–gel method, and the effect of Mn3+ doping on the structural morphology and electronic structure of La–Sr ferrite was studied. Mössbauer spectrum test results show that with the increase in the doping ratio of Mn3+, the percentage of double peaks gradually increases. When x = 0.5, all the sextet disappeared and only the doublet existed. The analysis shows that Mn3+ doping led to the transition of La–Sr ferrite from antiferromagnetic to paramagnetic. [ABSTRACT FROM AUTHOR]

Thermally induced spin control is one of the main directions for future spin devices. In this study, we synthesized single-phase polycrystalline ErFe 1 − x CrxO3 and combined the magnetization curves and Mössbauer spectra to determine the macroscopic magnetism at room temperature (RT). The magnetization of the system at various temperatures is well simulated by molecular field theory. And it is found that under the Dzyaloshinskii–Moriya (DM) interaction, not only the B-site ions undergo a reorientation process, but the spins of the A-site ions also change at the same time. The effective spin is defined as the projection of Er 3 + on the Fe 3 + /Cr 3 + spin plane, and the whole reorientation process is obtained by fitting. This study will complement the actual process of ErFe 1 − x CrxO3 spin reorientation and will lay a theoretical foundation for the fabrication of future spin-controlled devices. Under the control of a certain temperature, the magnetic rare earth perovskite EFCO, in addition to the known spin reorientation of the B-site ions, also has a special spin turn of the A-site rare earth ions, that is, the value of the effective spin (the projection of the full spin on the B-site spin plane) also changes. [ABSTRACT FROM AUTHOR]

• The thermomagnetic curve of NdFe 0.5 Cr 0.5 O 3 composite system was simulated by molecular field model and Monte Carlo method. • It was found that due to the random distribution of B site ions in NdFe 0.5 Cr 0.5 O 3 , cluster complexes with multiple Fe or Cr are easy to appear, and have complementary proportions. • In the process of spin reorientation, the effective spin of Nd3+ion at A site will also change with temperature. • The exchange constant of each phase in the composite system is estimated. Sophisticated spin instruments require high-precision spin control. In this study, we accurately study the intrinsic magnetic properties of the strongly disordered system NdFe 0.5 Cr 0.5 O 3 through molecular field models combined with anti-site defects (ASD) theory. The three constituent sub-magnetic phases of the system are separated, and their magnetization contributions are calculated separately. Fitting the angle of the A/B magnetic moment at a given temperature, the reorientation temperature point and temperature dependence of different magnetic phases are obtained. This research will provide a very good theoretical support for studying complex disordered systems and applying high-precision spin control and lay a foundation for the design of new functional materials. [ABSTRACT FROM AUTHOR]