Ferromagnetic resonance and magnetization studies in exchange-coupled NiFe/Cu/NiFe structures

Nagamine, L.C.C.M.; Geshev, J.; Menegotto, Thiago; Fernandes, Antônio Alberto Ribeiro; Biondo, A.; Baggio-Saitovitch, E.

doi:10.1016/j.jmmm.2004.09.007

Cited by 18 publications

(10 citation statements)

References 31 publications

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“…This is also reflected in the ratio between the intensities I 1 /I 2 of the two resonance modes for θ H ¼0. Reduced effective magnetizations, calculated from FMR data measured at the X-band, were also reported for NiFe/Cu/NiFe trilayers with NiFe thicknesses less than 50 Å [15], grown on Si by sputtering deposition, in which, the 4πM eff are in good agreement with the reported ones here.…”

Section: The Nife(50 å)/V(t)/nife(30 å) Trilayers Systemsupporting

confidence: 87%

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Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Alayo

Pelegrini

Baggio-Saitovitch

2015

Journal of Magnetism and Magnetic Materials

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a b s t r a c tThe Ni 81 Fe 19 /V/Ni 81 Fe 19 heterostructures has been produced by magnetron sputtering and analyzed by ferromagnetic resonance. Two systems were investigated: the non symmetrical NiFe(50 Å)/V(t)/NiFe (30 Å) trilayers and the symmetrical NiFe(80 Å)/V(t)/NiFe(80 Å) trilayers, with variable ultrathin V thickness t. Ferromagnetic exchange coupling was evidenced for t below 10 Å by the excitation of the optic mode, in the case of the non symmetrical samples, and by the observation of a single resonance mode for the symmetrical trilayers. For larger V thickness, all samples exhibited two modes, which were attributed to the resonance of the individual NiFe layers with different effective magnetizations. The analysis with the equilibrium and resonance conditions provided the exchange coupling constants and effective magnetizations.

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Section: The Nife(50 å)/V(t)/nife(30 å) Trilayers Systemsupporting

confidence: 87%

“…One of the series of samples are the Si/NiFe(50 Å)/V(t)/NiFe(30 Å)/Ta heterostructures, with the V thickness of t¼5, 7,8,9,10,15,20 and 100 Å. In this series, the NiFe layers have different thickness.…”

Section: Samples and Experimental Detailsmentioning

confidence: 99%

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Alayo

Pelegrini

Baggio-Saitovitch

2015

Journal of Magnetism and Magnetic Materials

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“…11,16,18,[29][30][31][32][33]53 The magnetic parameters used in simulations were: the saturation magnetization M s = 800 emu/ cc, the exchange constant A =13ϫ 10 −12 J / m, the gyromagnetic ratio ␥ / 2 = 2.95 MHz/ Oe. 11,55 We use the code object oriented micromagnetic framework ͑OOMMF͒ 56 with the LLG equation of motion modified by a term that includes the interaction with a spin polarized current. 1 Using this code, magnetization dynamics can be explored as a function of current, applied magnetic field, and the sizes/shape of the free layer and polarizer.…”

Section: Appendixmentioning

confidence: 99%

Limits for the vortex state spin torque oscillator in magnetic nanopillars: Micromagnetic simulations for a thin free layer

Aranda

González

Val

et al. 2010

Journal of Applied Physics

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Anomalous magnetic properties of 7nm single-crystal Co3O4 nanowires J. Appl. Phys. 111, 013910 (2012) High field-gradient dysprosium tips for magnetic resonance force microscopy Appl. Phys. Lett. 100, 013102 (2012) Dipolar interactions in magnetic nanowire aggregates J. Appl. Phys. 110, 123924 (2011) Dielectric and spin relaxation behaviour in DyFeO3 nanocrystals J. Appl. Phys. 110, 124301 (2011) Finite size versus surface effects on magnetic properties of antiferromagnetic particles Appl. Phys. Lett. 99, 232507 (2011) Additional information on J. Appl. Phys. We report micromagnetic simulations of magnetization dynamics of a vortex state in the free layer of a circular nanopillar excited by the spin transfer torque effect of a perpendicular to the layer ͑dot͒ plane spin-polarized electrical current. The magnetization of the reference layer ͑polarizer͒ is assumed to be fixed. A new regime of the dynamic magnetization response to the current is reported: vortex expelling from the dot, subsequent in-plane magnetization oscillations in single domain state, and the vortex return with an opposite core polarization. We analyze conditions ͑limits of the vortex state as a nano-oscillator͒ to achieve steady magnetization oscillations corresponding to a gyrotropic motion of the vortex core in terms of the current intensity. These conditions are formulated via the critical currents and vary greatly with the magnetic damping parameter and the cell size used for micromagnetic simulations. The existing experiments on the current induced magnetization dynamics in nanopillars and nanocontacts are discussed.

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“…9,10 Brillouin light scattering 11 and ferromagnetic resonance 12 are usually used to determine the coupling constants and to study the spinwave modes, but only methods using pulsed excitation can reach the switching regime. At high excitation amplitudes, the motion of the magnetization becomes enharmonic, and it is best modeled by solving the Landau-Lifshitz-Gilbert ͑LLG͒ equation numerically.…”

Section: ͑1͒mentioning

confidence: 99%

Frequency- and time-domain investigation of the dynamic properties of interlayer-exchange-coupledNi81Fe19∕Ru∕Ni81
Belmeguenai
¹
,
Martin
²
,
Woltersdorf
³

et al. 2007
Phys. Rev. B
89
3
48
2
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Pulsed inductive microwave magnetometer ͑PIMM͒, conventional ferromagnetic resonance ͑FMR͒, and vector network analyzer FMR ͑VNA-FMR͒ have been used for complementary studies of the various excited modes in exchange-coupled NiFe͑30 nm͒ /Ru͑d Ru ͒ / NiFe͑30 nm͒ films with variable Ru thicknesses d Ru . For antiferromagnetically coupled layers, two modes, which vary in their relative intensity as a function of the bias field, are detected. These two modes, which are observable simultaneously over a limited range of the bias field with PIMM, are identified as optic and acoustic modes. The mode frequencies and the interlayer exchange coupling are found to oscillate as a function of the Ru layer thickness with a period of 8.5 Å. The frequency oscillations of the optic mode are coupling dependent, while those of the acoustic mode are indirectly related to coupling via the canting angle of the layer magnetizations below the saturation. Comparison between PIMM and VNA-FMR in terms of frequency of modes shows good agreement, but the optic mode is observed over a wider field range with VNA-FMR. Furthermore, we clearly observed different behaviors of the FMR linewidths as a function of the spacer thickness for the optic and acoustic modes. In addition, perpendicular standing spin waves have been studied as a function of coupling. The FMR linewidth of the different modes increases with the microwave frequency and typical damping constants of ␣ = 0.0073 have been measured. The effect of the pulse field amplitudes on the properties of the various excited modes has been simulated and studied experimentally.

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Ferromagnetic resonance and magnetization studies in exchange-coupled NiFe/Cu/NiFe structures

Cited by 18 publications

References 31 publications

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Limits for the vortex state spin torque oscillator in magnetic nanopillars: Micromagnetic simulations for a thin free layer

Frequency- and time-domain investigation of the dynamic properties of interlayer-exchange-coupledNi81Fe19∕Ru∕Ni81
Belmeguenai
¹
,
Martin
²
,
Woltersdorf
³

et al. 2007
Phys. Rev. B
89
3
48
2
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Ferromagnetic resonance and magnetization studies in exchange-coupled NiFe/Cu/NiFe structures

Cited by 18 publications

References 31 publications

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

Limits for the vortex state spin torque oscillator in magnetic nanopillars: Micromagnetic simulations for a thin free layer

Frequency- and time-domain investigation of the dynamic properties of interlayer-exchange-coupledNi81Fe19∕Ru∕Ni81Belmeguenai1, Martin2, Woltersdorf3 et al. 2007Phys. Rev. B893482View full textAdd to dashboardCite

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Frequency- and time-domain investigation of the dynamic properties of interlayer-exchange-coupledNi81Fe19∕Ru∕Ni81
Belmeguenai
¹
,
Martin
²
,
Woltersdorf
³

et al. 2007
Phys. Rev. B
89
3
48
2
View full text Add to dashboard Cite