TY - JOUR
T1 - Amplitude and phase of higher harmonic of magnetic nanoparticles’ magnetization under low frequency magnetic field
AU - Du, Zhongzhou
AU - Sun, Yi
AU - Wang, Dandan
AU - Higashi, Oji
AU - Bai, Shi
AU - Noguchi, Yuki
AU - Enpuku, Keiji
AU - Yoshida, Takashi
N1 - Funding Information:
This work was supported in part by National Natural Science Foundation of China 61803346, Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research (S) JP15H05764, Grant-in-Aid for Scientific Research (C) JP18K04170, Grant-in-Aid for JSPS Fellows JP18F18760, and Science and Technology Program of Henan, China 192102310213.
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/8/15
Y1 - 2020/8/15
N2 - The rotational relaxations exist in magnetic nanoparticles (MNPs) exposed to AC excitation magnetic field, including Brownian rotational relaxation and Neel rotational relaxation. The magnetization of MNPs exposed in AC magnetic field may be affected by rotational relaxation (Brownian relaxation play a dominated role when frequency is less than 1 kHz), and phase lag of magnetization harmonics are existed. In this paper, we employ a Fokker-Planck Equation, which describe accurately AC magnetization dynamic (dominated by Brownian rotational relaxation), analyze the difference of AC magnetization based on Fokker-Planck Equation and Langevin Function, study magnetization harmonic and phase lag dependence on Brownian rotational relaxation, impose a simple, empirical harmonic model. The simulation and experiment results show that the harmonic model can describe accurately AC magnetization when the Brownian rotational relaxation is dominated in MNPs. It is expected to be useful for improving MPI and MNPT.
AB - The rotational relaxations exist in magnetic nanoparticles (MNPs) exposed to AC excitation magnetic field, including Brownian rotational relaxation and Neel rotational relaxation. The magnetization of MNPs exposed in AC magnetic field may be affected by rotational relaxation (Brownian relaxation play a dominated role when frequency is less than 1 kHz), and phase lag of magnetization harmonics are existed. In this paper, we employ a Fokker-Planck Equation, which describe accurately AC magnetization dynamic (dominated by Brownian rotational relaxation), analyze the difference of AC magnetization based on Fokker-Planck Equation and Langevin Function, study magnetization harmonic and phase lag dependence on Brownian rotational relaxation, impose a simple, empirical harmonic model. The simulation and experiment results show that the harmonic model can describe accurately AC magnetization when the Brownian rotational relaxation is dominated in MNPs. It is expected to be useful for improving MPI and MNPT.
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U2 - 10.1016/j.jmmm.2020.166886
DO - 10.1016/j.jmmm.2020.166886
M3 - Article
AN - SCOPUS:85083027225
SN - 0304-8853
VL - 508
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
M1 - 166886
ER -