Theoretical Model of Electric Field Tunable FMR Frequency of Magnetoelectric Tri-Layered Structure

2013 ◽  
Vol 303-306 ◽  
pp. 16-21
Author(s):  
Hao Miao Zhou ◽  
Qing Chen ◽  
Juan Hu Deng ◽  
Ying Xiao
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Electric Field ◽  
Frequency Shift ◽  
Free Energy Density ◽  
Coupling Mechanism ◽  
Mechanical Coupling ◽  
Out Of Plane ◽  
Magnetostriction Coefficient ◽  
Ferromagnetic Resonance Frequency

To study the magnetic-electrical-mechanical coupling mechanism of microwave ME (magnetoelectric) tri-layered structures, we proposed a theoretical model of electric tunable FMR (Ferromagnetic Resonance) frequency shift for bias magnetic field in different directions through the theory of Smith-Beljers and free energy density of ferrite. A deformation produced by the applied electric field called strain could be obtained through the theory of classical laminated plate. This model effectively predicts the stress of laminated structure increases when the piezoelectric coefficient increases, the shift of electric field tunable FMR frequency is more obvious when saturation magnetization and magnetostriction coefficient of ferrite increase. Moreover, it qualitatively explains the experimental phenomena that the directions of FMR frequency shift are opposite when apply the in-plane and out-of-plane magnetic field respectively, and provides a theoretical basis for electric field and magnetic field dual tunable microwave devices.

MMS Observation of Intermittent Energy Dissipation in Magnetic Reconnection Diffusion Region

2021 ◽  
Author(s):  
Xiangcheng Dong ◽  
Malcolm Dunlop ◽  
Tieyan Wang ◽  
Jinsong Zhao ◽  
Huishan Fu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Dissipation ◽  
Electric Field ◽  
Comparative Study ◽  
Spatial Effect ◽  
Diffusion Region ◽  
Common Phenomenon ◽  
Magnetospheric Multiscale ◽  
Out Of Plane ◽  
Current Behavior

<p>Magnetospheric Multiscale (MMS) data are used to investigate the energy dissipation in a  reconnection diffusion region at the magnetopause. The four MMS spacecraft were separated by about 10 km such that comparative study between each spacecraft within the diffusion region can be implemented. Similar magnetic field and electric current behavior between each spacecraft indicates the formation of a quasi-homogeneous diffusion region structure. However, we find that the energy dissipation results between each spacecraft are different due to the temporal or spatial effect of the out-of-plane merging electric field (E<sub>M</sub>) during the dissipation region. Our study suggests that the intermittent energy dissipation in the reconnection dissipation region can be a common phenomenon, even under a stable diffusion region structure.</p>

scholarly journals Disturbed vertical E×B plasma drifts in the equatorial F2 region at solar minimum deduced from observed NmF2 and hmF2 variations

1996 ◽  
Vol 14 (7) ◽  
pp. 733-743 ◽  
Author(s):  
A. V. Mikhailov ◽  
M. Förster ◽  
T. Y. Leschinskaya
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Electric Field ◽  
Solar Minimum ◽  
Strong Dependence ◽  
Field Observations ◽  
Model Calculations ◽  
Equatorial Station ◽  
Plasma Drift ◽  
Model Predictions

Abstract. Ground-based ionosonde and magnetic-field observations on the equatorial station Huancayo, ESRO4 neutral-composition measurements, and theoretical model calculations were used to analyze disturbed E×B vertical plasma drift during the phase of solar minimum in 1973. Vertical drifts calculated for disturbed days do not show the systematic decrease often mentioned in publications, and demonstrate strong dependence on IMF-Bz changes. It is confirmed with the help of our drift calculations that Bz turnings to a northward direction result in a decrease (up to reversal) of normal Sq (eastward during daytime and westward at nighttime) in the zonal component of electric field. Southward Bz excursions enhance normal Ey both in daytime and nighttime hours. Model predictions of Ey\\'s reaction to IMF-Bz changes are discussed.

scholarly journals Role of Parallel Solenoidal Electric Field on Energy Conversion in 2.5D Decaying Turbulence with a Guide Magnetic Field

2021 ◽  
Vol 923 (2) ◽  
pp. 182
Author(s):  
Peera Pongkitiwanichakul ◽  
David Ruffolo ◽  
Fan Guo ◽  
Senbei Du ◽  
Piyawat Suetrong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Transfer ◽  
Kinetic Energy ◽  
Electric Field ◽  
Electromagnetic Energy ◽  
Plasma Kinetic ◽  
Background Magnetic Field ◽  
Out Of Plane ◽  
Decaying Turbulence ◽  
Guide Magnetic Field

Abstract We perform 2.5D particle-in-cell simulations of decaying turbulence in the presence of a guide (out-of-plane) background magnetic field. The fluctuating magnetic field initially consists of Fourier modes at low wavenumbers (long wavelengths). With time, the electromagnetic energy is converted to plasma kinetic energy (bulk flow+thermal energy) at the rate per unit volume of J · E for current density J and electric field E . Such decaying turbulence is well known to evolve toward a state with strongly intermittent plasma current. Here we decompose the electric field into components that are irrotational, E ir, and solenoidal (divergence-free), E so. E ir is associated with charge separation, and J · E ir is a rate of energy transfer between ions and electrons with little net change in plasma kinetic energy. Therefore, the net rate of conversion of electromagnetic energy to plasma kinetic energy is strongly dominated by J · E so, and for a strong guide magnetic field, this mainly involves the component E so,∥ parallel to the total magnetic field B . We examine various indicators of the spatial distribution of the energy transfer rate J ∥ · E so,∥, which relates to magnetic reconnection, the best of which are (1) the ratio of the out-of-plane electric field to the in-plane magnetic field, (2) the out-of-plane component of the nonideal electric field, and (3) the magnitude of the estimate of current helicity

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