Magnetization switching modes in nanopillar spin valve under the external field

Applied Physics Letters

Yang

et al. 2014

Effect of substrate misfit strain on current-induced in-plane magnetization reversal in CoFeB-MgO based magnetic tunnel junctions is investigated by combining micromagnetic simulations with phase-field microelasticity theory. It is found that the critical current density for in-plane magnetization reversal decreases dramatically with an increasing substrate strain, since the effective elastic field can drag the magnetization to one of the four in-plane diagonal directions. A potential strainassisted multilevel bit spin transfer magnetization switching device using substrate misfit strain is also proposed. V

mentioning

confidence: 99%

Strain-assisted current-induced magnetization reversal in magnetic tunnel junctions: A micromagnetic study with phase-field microelasticity

Applied Physics Letters

Yang

et al. 2014

“…The dynamics of magnetization is investigated by numerically solving the timedependent LLGS equation using the Gauss-Seidel projection method with a constant time step ∆t= 0.0268858 ps. [36][37][38] We adopted the following magnetic parameters, magnetocrystalline anisotropy constant K 1 =3.0×10 3 J/m 3 , and K 2 =0, 39 exchange constant A=2.0×10 -11 J/m, 40 saturation magnetization M s =8.0×10 5 A/m. 41 Other parameters are Gilbert damping parameter α=0.008, 14 spin polarization factor η=0.56, 42,43 electron gyromagnetic ratio γ=2.3245×10 5 For clarify, the PSD of y axis shifts up with 0.5 each curve with the increase of external stress.…”

Section: Methodsmentioning

confidence: 99%

Simulation of stress-modulated magnetization precession frequency in Heusler-based spin torque oscillator

Journal of Magnetism and Magnetic Materials

Zhao

2017

Self Cite

We investigated stress-modulated magnetization precession frequency in Heuslerbased spin transfer torque oscillator by combining micromagnetic simulations with phase field microelasticity theory, by encapsulating the magnetic tunnel junction into multilayers structures. We proposed a novel method of using an external stress to control the magnetization precession in spin torque oscillator instead of an external magnetic field. The stress-modulated magnetization precession frequency can be linearly modulated by externally applied uniaxial in-plane stress, with a tunable range 4.4~7.0 GHz under the stress of 10MPa. By comparison, the out-ofplane stress imposes negligible influence on the precession frequency due to the large out-of-plane demagnetization field. The results offer new inspiration to the design of spin torque oscillator devices that simultaneously process high frequency, narrow output band, and tunable over a wide range of frequencies via external stress.

“…29 The initial magnetizations of free and pinned layers are along the Àx axis and þx axis, respectively. The dynamics of magnetization was investigated by numerically solving the time-dependent LLGS equation using the Gauss-Seidel projection method [33][34][35][36] with a constant time step Dt ¼ 0.0238993 ps. The samples were discrete in computational cells of 2 Â 2 Â 2 nm 3 .…”

Section: Model Descriptionmentioning

confidence: 99%

Modelling current-induced magnetization switching in Heusler alloy Co2FeAl-based spin-valve nanopillar

Journal of Applied Physics

Liu

et al. 2014

We investigated the current-induced magnetization switching in a Heusler alloy Co 2 FeAl-based spin-valve nanopillar by using micromagnetic simulations. We demonstrated that the elimination of the intermediate state is originally resulted from the decease of effective magnetic anisotropy constant. The magnetization switching can be achieved at a small current density of 1.0 Â 10 4 A/cm 2 by increasing the demagnetization factors of x and y axes. Based on our simulation, we found magnetic anisotropy and demagnetization energies have different contributions to the magnetization switching. V