Magnetization of ferromagnetic polycrystals subject to an external magnetic field

The mutual control mechanism between magnetization and polarization in multiferroic materials is studied. The system contains a ferromagnetic sublattice and a ferroelectric sublattice. To describe the magneto-electric coupling, we propose a linear coupling Hamiltonian between ferromagnetism and ferroelectricity without microscopic derivation. This coupling enables one to retrieve the hysteresis loops measured experimentally. The thermodynamic properties of the system are calculated, such as the temperature dependences of the magnetization, polarization, internal energy and free energy. The ferromagnetic and ferroelectric hysteresis loops driven by either a magnetic or an electric field are calculated, and the magnetic spin and pseudo-spin are always flipped synchronously under the external magnetic and electric field. Our theoretical results are in agreement with the experiments.

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“…The FM subsystem is described by the Heisenberg model and the spontaneous magnetization is along the z direction. The Hamiltonian reads [26,27]…”

Section: Model and Methodsmentioning

confidence: 99%

Theoretical study of mutual control mechanism between magnetization and polarization in multiferroic materials

2015

Self Cite

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“…When the ferromagnetic body is subjected to applied magnetic fields or stresses, the difference of mode and degree among internal magnetic domain motion leads to different magnetic domain structure in the final stable state [13–15 ], which macroscopically represents the different magnetisation state of the ferromagnetic body [16 ]. Since the loaded ferromagnetic body is in different initial magnetisation state, the domain wall displacement and rotation occur in different ways, which results in variation of magnetisation [17, 18 ].…”

Section: Mathematical Modellingmentioning

confidence: 99%

Research on stress detection technology of long-distance oil and gas pipeline based on magnetomechanics characteristics

Liu

Wang

et al. 2020

IET Science, Measurement &Amp; Technology

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Magnetic memory stress detection technology has broad application prospects in the field of stress detection in long‐distance oil and gas pipelines because it supports non‐contact and dynamic on‐line detection. However, the magnetic memory signal is weak and susceptible to an external magnetic field. A J‐A model is established to quantitatively study the distribution characteristics of the magnetic memory signal in the stress concentration area of the pipeline. In this study, the mathematical model of magnetomechanics of the pipeline is established. The variation law of magnetic memory signal in the stress concentration area with the external magnetic field is calculated and analysed. A systematic experimental study is carried out. The results show that the magnetic memory signal linearly changes with stress in the geomagnetic field, and magnetic memory signal characteristics of circumferential stress with internal pressure is larger than the axial one. The amplitude of the magnetic memory signal in the stress concentration area increases with the increase in magnetic field intensity of the weak magnetic field, meantime the magnetic sensitivity decreases. The magnetic memory signal in the stress concentration area of the pipeline in magnetic saturation is covered by the strong magnetic field resulting in an undetected stress concentration area.

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“…[25][26][27][28] In this paper, we will apply TGFM to investigate the magnetic properties of La 1−x Sr x MnO 3 by means of the three-dimensional mixedspin Heisenberg model. Moreover, TGFM is valid over the whole temperature range and takes into account the spin fluctuation.…”

Section: Introductionmentioning

confidence: 99%

The three-dimensional mixed-spin Heisenberg model applied to the magnetic properties of La1−xSrxMnO3 in the random phase approximation

Chen

Wang

2010

Journal of Applied Physics

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Articles you may be interested inThree-dimensional strain state and spacer thickness-dependent properties of epitaxial Pr0.7Sr0.3MnO3/La0.5Ca0.5MnO3/Pr0.7Sr0.3MnO3 trilayer structureThe magnetic properties of the manganese oxide compounds La 1−x Sr x MnO 3 are studied by means of the double-time Green's function. The phase diagram, magnetization, spin-wave dispersion, and spin-wave stiffness are obtained within the random phase approximation. Our results are in agreement with other theoretical and experimental results.

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Magnetization of ferromagnetic polycrystals subject to an external magnetic field

Cited by 9 publications

References 22 publications

Theoretical study of mutual control mechanism between magnetization and polarization in multiferroic materials

Theoretical study of mutual control mechanism between magnetization and polarization in multiferroic materials

Research on stress detection technology of long-distance oil and gas pipeline based on magnetomechanics characteristics

The three-dimensional mixed-spin Heisenberg model applied to the magnetic properties of La1−xSrxMnO3 in the random phase approximation

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