Magnetization relaxation and structure of CoFeGe alloys

Lee, H.; Wang, Y.-H. A.; Mewes, Claudia; Butler, W. H.; Mewes, Tim; Maat, S.; York, Brian; Carey, M. J.; Childress, J. R.

doi:10.1063/1.3207749

Cited by 52 publications

(34 citation statements)

References 12 publications

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“…As each contribution to the linewidth present a different evolution with the applied field intensity or field angle, it is possible to evaluate the contribution from each one to the total linewidth [30,31].…”

Section: High Frequency Permeability Measurementsmentioning

confidence: 99%

A study on the thickness dependence of static and dynamic magnetic properties of Ni81Fe19 thin films

Kern

Silva

Siqueira

et al. 2016

Journal of Magnetism and Magnetic Materials

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Section: High Frequency Permeability Measurementsmentioning

confidence: 99%

A study on the thickness dependence of static and dynamic magnetic properties of Ni81Fe19 thin films

Kern

Silva

Siqueira

et al. 2016

Journal of Magnetism and Magnetic Materials

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“…We observed non-linear behavior in the linewidth vs. frequency response along the magnetic easy axis. This nonlinear dependence of the FMR linewidth on frequency is a typical observation when two magnon scattering contributes significantly to the relaxation [22,23]. Two-magnon scattering is an extrinsic relaxation mechanism and can be induced by means of different scattering centers such as voids or pores [24], surface roughness [22] and grain size [25] or by network of misfit dislocations which causes scattering of the FMR mode (k=0) into propagating spin waves (k =0).…”

Section: Magnetization Dynamicsmentioning

confidence: 99%

Low Gilbert damping in Co2FeSi and Fe2CoSi films

Sterwerf

Paul

Khodadadi

et al. 2016

Journal of Applied Physics

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Thin highly textured Fe1+xCo2−xSi (0 ≤ x ≤ 1) films were prepared on MgO (001) substrates by magnetron co-sputtering. The magneto-optic Kerr effect (MOKE) and ferromagnetic resonance (FMR) measurements were used to investigate the composition dependence of the magnetization, the magnetic anisotropy, the gyromagnetic ratio and the relaxation of the films. The effective magnetization for the thin Fe1+xCo2−xSi films, determined by FMR measurements, are consistent with the Slater Pauling prediction. Both MOKE and FMR measurements reveal a pronounced fourfold anisotropy distribution for all films. In addition we found a strong influence of the stoichiometry on the anisotropy as the cubic anisotropy strongly increases with increasing Fe concentration. The gyromagnetic ratio is only weakly dependent on the composition. We find low Gilbert damping parameters for all films with values down to 0.0012 ± 0.00012 for Fe1.75Co1.25Si. The effective damping parameter for Co2FeSi is found to be 0.0018 ± 0.0004. We also find a pronounced anisotropic relaxation, which indicates significant contributions of two-magnon scattering processes that is strongest along the easy axes of the films. This makes thin Fe1+xCo2−xSi films ideal materials for the application in STT-MRAM devices.

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“…The breathing Fermi surface model [22] and torque-correlation model [23] based on first principle band structure calculations qualitatively match α 0 in soft magnetic alloys such as Fe, Co and Ni [32][33][34][35][36][37]. Moreover, contributions to α 0 can be categorized based on intraband and interband transitions [23,26].…”

Section: Introductionmentioning

confidence: 99%

Role of antisite disorder on intrinsic Gilbert damping inL10FePt films

et al. 2015

Phys. Rev. B

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The impact of anti-site disorder x on the intrinsic Gilbert damping α 0 in well-ordered 1 FePt films is investigated by time-resolved magneto-optical Kerr effect. The variation of x mainly affects the electron scattering rate 1/τ e , while other leading parameters remain unchanged. The experimentally observed linear dependence of α 0 on 1/τ e indicates that spin relaxation is through electron interband transitions, as predicted by spin-orbit coupling torque correlation model. Measurements at low temperature show that α 0 remains unchanged with temperature even for FePt with very high chemical order, indicating that electron-phonon scattering is negligible. Moreover, as x decreases the perpendicular magnetic anisotropy increases and the Landau g factor exhibits a negative shift due to an increase in orbital momentum anisotropy. Our results will facilitate the design and exploration of new magnetic alloys with large magnetic anisotropy and desirable damping properties.PACS numbers: 75.78. Jp, 75.70.Tj, 75.50.Vv, 75.30.Gw + e-mail: hbzhao@fudan.edu.cn *e-mail: gxluep@wm.edu.[2] IntroductionUltrafast magnetization precessional switching in ferromagnets utilizing magnetic field pulses, spin polarized currents, and ultrafast laser pulses [1][2][3][4][5][6] is currently a popular topic due to its importance in magnetic information storage and spintronic applications. The uniform magnetization precession can be well modeled with Landau-Lifshitz-GilbertSlonczewski (LLGS) equation [7][8][9], where the Slonczewski torque term denotes the spin transfer torques (STTs), and the Gilbert damping parameter α determines the spin relaxation time [10] and is crucial for device performance [11][12][13][14]. The extrinsic Gilbert damping is due to nonlocal spin relaxation, such as spin pumping and magnon-magnon scattering, which can be tuned by artificial substrates, specially designed buffer and coverage layers [15][16][17][18][19][20][21], while the intrinsic Gilbert damping parameter α 0 is thought to arise from spin-orbit interaction (SOI) [22][23][24][25][26][27][28][29][30], and recently its quadratic dependence on SOI is demonstrated experimentally in FePtPd alloys [31].The α 0 describes the energy flow rate from spin to electronic orbital and phonon degrees of freedom through electron scattering, and has been studied in various theoretical models [22][23][24][25][26][27][28][29][30]. The breathing Fermi surface model [22] and torque-correlation model [23] based on first principle band structure calculations qualitatively match α 0 in soft magnetic alloys such as Fe, . Moreover, contributions to α 0 can be categorized based on intraband and interband transitions [23,26]. The damping rate from intraband transitions scales linearly with the electron relaxation time τ e and exhibits conductivity-like behavior. In contrast, the damping rate from the interband transition is proportional to the electron scattering rate 1/τ e , and consequently exhibits resistivity-like behavior. Therefore, the transition from conductivity-like to re...

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Magnetization relaxation and structure of CoFeGe alloys

Abstract: Articles you may be interested inStructure and magnetoresistance of current-perpendicular-to-plane pseudo spin valves using Co2Mn(Ga0.25Ge0.75) Heusler alloy

Cited by 52 publications

References 12 publications

A study on the thickness dependence of static and dynamic magnetic properties of Ni81Fe19 thin films

A study on the thickness dependence of static and dynamic magnetic properties of Ni81Fe19 thin films

Low Gilbert damping in Co2FeSi and Fe2CoSi films

Role of antisite disorder on intrinsic Gilbert damping inL10FePt films

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