Influence of frequency of the excitation magnetic field and material's electric conductivity on domain wall dynamics in ferromagnetic materials

Chavez-Gonzalez, A. F.; Benítez, José Alberto Pérez; Espina-Hernández, J.H.; Größinger, R.; Hallen, J.M.

doi:10.1016/j.jmmm.2015.10.045

“…The coercive decreases from 0.724 to 0.423 as the frequency f decrease from 2.5 × 10 −5 Hz to 0.833 × 10 −5 Hz, meanwhile, the remnant magnetizations are not affected. Such a simulation result agrees well with previous experimental reports [44][45][46].…”

Section: Resultssupporting

confidence: 92%

Effects of magnetic frequency and the coupled magnetic-mechanical loading on a ferromagnetic shape memory alloy

Wu

¹

,

Ke

²

,

Zhu

³

et al. 2021

J. Phys. D: Appl. Phys.

9

0

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In the present work, the microstructure evolution and macro-response of a ferromagnetic shape memory alloy under stimuli of magnetic fields with different frequency and coupled magnetic-mechanical loading are investigated via a real-space phase field simulation. It is found that the coercive field is reduced from 0.724 to 0.423 with the magnetic frequency f decrease from 2.5 × 10 − 5 Hz to 0.833 × 10 − 5 Hz, wherein the concomitant domain wall motion and magnetization rotation are captured as well. Moreover, simulation results demonstrate that, under the coupled magnetic-mechanical loading, the coercive field of the magnetic hysteresis loop could be reduced by applying a compressive strain perpendicular to the magnetic field direction. The domain evolution is mainly divided into three types during the coupled magnetic-mechanical loading, namely (a) domain wall motion with the magnetization rotation, (b) pure magnetization rotation, and (c) 180° domain coordinated domain switching. To better understand the domain evolution, we propose an index S = m 1 avg + m 2 avg , with m 1 avg and m 2 avg indicating the absolute value of the averaged magnetization component m 1 and m 2 over the whole studied system, to characterize the magnetization change during the microstructure evolution.

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“…Figures 7 and 8 show the MBN profiles for the samples PA_2 and PA_M2, in which peak value of the fitted profiles first increases and then decreases with frequency of the excitation field, and it is highest when frequency equals 50 Hz for both the samples. It is evident as there is optimum frequency at which the signal has maximum strength because MBN signal, according to Faraday's law, is given as v MBN = −nS dB dt , where B = o (H + M) is magnetic induction field, and the peak value depends upon two factors: the rate of change of magnetic field intensity dH dt = 2 fH a cos(2 t * ) , which increases with frequency as H a , which is the amplitude of the magnetic field intensity, is constant and the rate of change of magnetization dM dt ∝ (domain wall velocity) , which decreases with frequency due to proportional increase in coercive field of the pinning sites as a result of induced eddy current in the specimen [27,29]. The peak occurs before t* < 0.5 for all the samples that is along the path f-a in B-H curve (refer Fig.…”

Section: Effect Of Frequency On the Mbn Profilementioning

confidence: 99%

“…According to the Pérez-Benítez model [26], the MBN is produced by the interaction of domain walls with defects, where the coercive field of these defects follows a Gaussian distribution function. Chávez-González et al [27] also proposed a model based on [26], but also took eddy currents into account.…”

Section: Introductionmentioning

confidence: 99%

Barkhausen noise signal of different steels upon face-turning process

Vineet

¹

,

Vashista

²

,

KhanYusufzai

³

2019

J Braz. Soc. Mech. Sci. Eng.

0

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This paper deals with understanding the effects of excitation field parameters on the nature of Barkhausen noise profile in order to improve the validity of Barkhausen noise results for the machining process. The experiment has been performed on total of four samples, two of high carbon steel and two of high carbon chromium steel. First, all samples are subjected to process annealing and later one sample of each steel was subjected to face-turning process. Barkhausen noise measurement was performed in two steps: first, magnetizing frequency varied and magnetic field intensity kept constant, and second, magnetic field intensity varied and magnetizing frequency kept constant. Magnetic Barkhausen noise profile is obtained by fitting Gaussian function to the root-mean-square distribution of the Barkhausen signal. The complicated behaviour of the profiles with frequency suggests optimum frequency determined statistically, which reflects the stochastic behaviour and can be applied to describe and control the face-turning process. The peak value of the profiles with amplitude of the sinusoidal magnetic field intensity has found to resemble exponential decay correlation.

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“…As frequency-mixing is generated in the nonlinear interaction between two magnetic fields and the magnetic microstructure, the excitation parameters for the two magnetic fields inevitably influence the performance of magnetic frequency mixing detection given the same test ferromagnetic material [12][13][14]. Burdin et al [15] analyzed the influence of the frequency and amplitude of the high-frequency magnetic field on frequency mixing effect by experiment.…”

Section: Introductionmentioning

confidence: 99%

Application of Uniform Experimental Design in Optimizing Excitation Parameters for Magnetic Frequency Mixing Measurements

Chang

¹

,

Jiao

²

,

Liu

³

et al. 2020

Chin. J. Mech. Eng.

2

0

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Excitation parameter preferences are key factors affecting the performance of magnetic frequency mixing detection. A uniform experimental design method was used to analyze this influence. Using fuzzy theory, a comprehensive model is established for evaluating the effect of magnetic frequency mixing. A polynomial is selected as the regression function to express explicitly the correlation between the excitation parameters and the frequency-mixing effect. The excitation parameters were then optimized using genetic algorithm. Magnetic frequency mixing experiments were conducted to measure the surface hardness of some ferromagnetic materials. Frequency mixing is further enhanced under the optimal settings, resulting in an improvement in the measurement sensitivity. The results of this study support the application of the magnetic frequency mixing technique in non-destructive testing. , respectively. He is currently a professor at Beijing University of Technology. His main research interests include mechanical testing theory method and technology, ultrasonic nondestructive testing technology, and sensor technology. Bin Wu received his BS, MS and PhD degree in 1984, 1990 and 1996 from Tianjin University, Beijing University of Aeronautics and Astronautics and Taiyuan University of Technology, respectively. He is currently a professor at Beijing University of Technology. His main research interests include experimental solid mechanics, modern measurement and control technology, nondestructive testing of new technology, and new sensor technology.

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Influence of frequency of the excitation magnetic field and material's electric conductivity on domain wall dynamics in ferromagnetic materials

Cited by 8 publications

References 15 publications

Effects of magnetic frequency and the coupled magnetic-mechanical loading on a ferromagnetic shape memory alloy

Effects of magnetic frequency and the coupled magnetic-mechanical loading on a ferromagnetic shape memory alloy

Barkhausen noise signal of different steels upon face-turning process

Application of Uniform Experimental Design in Optimizing Excitation Parameters for Magnetic Frequency Mixing Measurements

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