Electric-field-induced ferromagnetic resonance excitation in an ultrathin ferromagnetic metal layer

2012 ◽  
Vol 8 (6) ◽  
pp. 491-496 ◽  
Author(s):  
Takayuki Nozaki ◽  
Yoichi Shiota ◽  
Shinji Miwa ◽  
Shinichi Murakami ◽  
Frédéric Bonell ◽  
...  
Keyword(s):  
Electric Field ◽  
Ferromagnetic Resonance ◽  
Metal Layer ◽  
Ferromagnetic Metal ◽  
Resonance Excitation

SPIN PUMPING IN FERROMAGNETIC MULTILAYERS

2008 ◽  
Vol 22 (30) ◽  
pp. 2909-2929 ◽  
Author(s):  
TOMOHIRO TANIGUCHI ◽  
HIROSHI IMAMURA
Keyword(s):  
Line Width ◽  
Ferromagnetic Resonance ◽  
Metal Layer ◽  
Spin Current ◽  
Theoretical Models ◽  
Ferromagnetic Metal ◽  
Transverse Spin ◽  
Spin Pumping ◽  
Ferromagnetic Metals ◽  
Penetration Depths

We present a brief review of our recent study on spin pumping in ferromagnetic multilayers. First, we present theoretical models describing spin pumping induced by ferromagnetic resonance (FMR). Then we apply the spin-pumping theory to FMR in ferromagnetic multilayers and show that the line width of the FMR spectrum depends on the thickness of the ferromagnetic metal layer which is not in resonance. We also show that the penetration depths of transverse spin current in ferromagnetic metals can be determined by analyzing the line width of the FMR spectrum. The obtained penetration depths of the transverse spin current were 3.7 nm for Py , 2.5 nm for CoFe , 12.0 nm for CoFeB , and 1.7 nm for Co , respectively.

scholarly journals Effects of Frequency and Temperature on Electric Field Mitigation Method via Protruding Substrate Combined with Applying Nonlinear FDC Layer in Wide Bandgap Power Modules

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2022 ◽  
Author(s):  
Maryam Mesgarpour Tousi ◽  
Mona Ghassemi
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
Metal Layer ◽  
Wide Bandgap ◽  
High Density ◽  
Field Calculation ◽  
Power Module ◽  
Temperature Dependent ◽  
Ac Electrical Conductivity ◽  
Power Modules

Our previous studies showed that geometrical techniques including (1) metal layer offset, (2) stacked substrate design and (3) protruding substrate, either individually or combined, cannot solve high electric field issues in high voltage high-density wide bandgap (WBG) power modules. Then, for the first time, we showed that a combination of the aforementioned geometrical methods and the application of a nonlinear field-dependent conductivity (FDC) layer could address the issue. Simulations were done under a 50 Hz sinusoidal AC voltage per IEC 61287-1. However, in practice, the insulation materials of the envisaged WBG power modules will be under square wave voltage pulses with a frequency of up to a few tens of kHz and temperatures up to a few hundred degrees. The relative permittivity and electrical conductivity of aluminum nitride (AlN) ceramic, silicone gel, and nonlinear FDC materials that were assumed to be constant in our previous studies, may be frequency- and temperature-dependent, and their dependency should be considered in the model. This is the case for other papers dealing with electric field calculation within power electronics modules, where the permittivity and AC electrical conductivity of the encapsulant and ceramic substrate materials are assumed at room temperature and for a 50 or 60 Hz AC sinusoidal voltage. Thus, the big question that remains unanswered is whether or not electric field simulations are valid for high temperature and high-frequency conditions. In this paper, this technical gap is addressed where a frequency- and temperature-dependent finite element method (FEM) model of the insulation system envisaged for a 6.5 kV high-density WBG power module will be developed in COMSOL Multiphysics, where a protruding substrate combined with the application of a nonlinear FDC layer is considered to address the high field issue. By using this model, the influence of frequency and temperature on the effectiveness of the proposed electric field reduction method is studied.

scholarly journals Probing electric field control of magnetism using ferromagnetic resonance

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Ziyao Zhou ◽  
Morgan Trassin ◽  
Ya Gao ◽  
Yuan Gao ◽  
Diana Qiu ◽  
...  
Keyword(s):  
Electric Field ◽  
Ferromagnetic Resonance ◽  
Field Control

scholarly journals Voltage control of ferromagnetic resonance

2016 ◽  
Vol 06 (02) ◽  
pp. 1630005 ◽  
Author(s):  
Ziyao Zhou ◽  
Bin Peng ◽  
Mingmin Zhu ◽  
Ming Liu
Keyword(s):  
Electric Field ◽  
Ferromagnetic Resonance ◽  
Exchange Coupling ◽  
Voltage Control ◽  
High Sensitivity ◽  
Microwave Devices ◽  
Coupling Mechanism ◽  
Volume Response ◽  
Time And Energy ◽  
Interfacial Charge

Voltage control of magnetism in multiferroics, where the ferromagnetism and ferroelectricity are simultaneously exhibiting, is of great importance to achieve compact, fast and energy efficient voltage controllable magnetic/microwave devices. Particularly, these devices are widely used in radar, aircraft, cell phones and satellites, where volume, response time and energy consumption is critical. Researchers realized electric field tuning of magnetic properties like magnetization, magnetic anisotropy and permeability in varied multiferroic heterostructures such as bulk, thin films and nanostructure by different magnetoelectric (ME) coupling mechanism: strain/stress, interfacial charge, spin–electromagnetic (EM) coupling and exchange coupling, etc. In this review, we focus on voltage control of ferromagnetic resonance (FMR) in multiferroics. ME coupling-induced FMR change is critical in microwave devices, where the electric field tuning of magnetic effective anisotropic field determines the tunability of the performance of microwave devices. Experimentally, FMR measurement technique is also an important method to determine the small effective magnetic field change in small amount of magnetic material precisely due to its high sensitivity and to reveal the deep science of multiferroics, especially, voltage control of magnetism in novel mechanisms like interfacial charge, spin–EM coupling and exchange coupling.

Electric-field induced nonlinear ferromagnetic resonance in a CoFeB/MgO magnetic tunnel junction

2015 ◽  
Vol 107 (13) ◽  
pp. 132404 ◽  
Author(s):  
E. Hirayama ◽  
S. Kanai ◽  
J. Ohe ◽  
H. Sato ◽  
F. Matsukura ◽  
...  
Keyword(s):  
Electric Field ◽  
Ferromagnetic Resonance ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction
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