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Jizhou Jiang

Publications and source records attributed to Jizhou Jiang.

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Unraveling the nature of thermally induced spin reorientation in NdFe1-xCrxO3

Understanding spin control mechanisms is an important part of condensed matter physics and the theoretical basis for designing spintronic devices. In this letter, based on four-sublattices molecular field theory, we propose that the underlying NdFe1-xCrxO3 magnetic mechanism is driven by spin reorientation sensitive to temperature. The actual coupling angular momentum, angle between the Nd3+ and Cr3+/Fe3+ moments at the given temperature is realized via the Nd3+ magnetic moment projection onto the Cr3+/Fe3+ plane. As the temperature increases, the angle between the moment of Nd3+ and the moment of Cr3+/Fe3+ decreases monotonically. In this work, the magnetic mechanism of NdFe1-xCrxO3 (x=0.1, 0.9), the close relationship between A/B angle and temperature are presented, which laid a theoretical foundation for the design of new multifunctional magnetic materials.

cond-mat.mtrl-sci

The distribution of B-site in the perovskite for a d5-d3 superexchange system studied with Molecular field theory and Monte Carlo simulation

The B-site disorder in the d5 - d3 system of perovskites has been analyzed with molecular field theory and Monte Carlo method. The model is applicable to RFe1-pCrpO3 at any p value. When the saturation magnetization MS and phase transition temperature TP are known, a model can be built to calculate the order or disorder distribution of lattice B-sites. We analyze the case that the Fe-Cr superexchange is antiferromagnetic and ferromagnetic coupling respectively. The simulation result shows that the theoretical calculation formula is suitable for the calculation of different B-site distribution. Through the simulation, we find that when the x and y are large, the system will appear obvious long-range order. The DM interaction has a certain influence on the saturation magnetization. Via calculation, we found that the distribution states of Fe and Cr do not always conform to the uniform distribution but rather exhibit an effect that reduces the Fe-Fe clustering. The establishment of this model offers an explanation for several previously contentious issues, e.g., what is the phase transition temperature range of double perovskite, and why the different phase transition temperatures with the same doping proportion. It provides theoretical guidance for the design of functional materials with an arbitrary phase transition temperature.

cond-mat.mtrl-sci