Spin Vortex Resonance in Non-planar Ferromagnetic Dots

Ding, J.; Lapa, Pavel N.; Jain, Shikha; Khaire, Trupti; Lendínez, Sergi; Zhang, Wei; Jungfleisch, M. Benjamin; Posada, C. M.; Yefremenko, V.; Pearson, John; Hoffmann, A.; Novosad, V.

doi:10.1038/srep25196

Cited by 6 publications

(4 citation statements)

References 23 publications

(36 reference statements)

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“…Discs of certain radius and height ratio exhibit a ground state referred to as a vortex 5,6 characterized by an in-plane magnetic flux closure. Since the magnetic moments are curling in-plane of the discs, the stray field from the discs is negligible when vortices are formed, in stark contrast to the collinear state [7][8][9][10] . The application of an external magnetic field drives the vortex core out of the center, towards the edge of the disc.…”

Section: Introductionmentioning

confidence: 99%

Collective magnetization dynamics in nanoarrays of thin FePd disks

et al. 2019

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We report on the magnetization dynamics of a square array of mesoscopic discs, fabricated from an iron palladium alloy film. The dynamics properties were explored using ferromagnetic resonance measurements and micromagnetic simulations. The obtained spectra exhibit features resulting from the interactions between the discs, with a clear dependence on both temperature and the direction of the externally applied field. We demonstrate a qualitative agreement between the measured and calculated spectra. Furthermore, we calculated the mode profiles of the standing spin waves excited during a time-dependent magnetic field excitations. The resulting maps confirm that the features appearing in the ferromagnetic resonance absorption spectra originate from the temperature and directional dependent inter-disc interactions. arXiv:1902.00403v1 [cond-mat.mes-hall]

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Section: Introductionmentioning

confidence: 99%

Collective magnetization dynamics in nanoarrays of thin FePd disks

et al. 2019

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“…This dependence on the geometrical properties and material properties poses an obstacle for realizing frequency tunability over a large range in a single spintorque-driven vortex oscillator, as only one frequency is possible for a given combination of h, R and M s . In order for a single device to be able to exhibit more than one frequency, two scenarios are possible: either spatially altering the topography 23 , or spatially varying the saturation magnetization. In this work, we show experimentally that by varying the M s of single disks using local ion beam irradiation, multiple gyrotropic frequencies can be obtained in single devices, thus allowing for frequency tunability.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

Tunable Magnetic Vortex Dynamics in Ion-Implanted Permalloy Disks

Ramasubramanian

Kákay

Fowley

et al. 2020

ACS Appl. Mater. Interfaces

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Nanoscale, low-phase noise, tunable transmitter-receiver links are key for enabling the progress of wireless communication. We demonstrate that vortex-based spin-torque nano-oscillators, which are intrinsically low-noise devices due to their topologically-protected magnetic structure, can achieve frequency tunability when submitted to local ion implantation. In the experiments presented here, the gyrotropic mode is excited with spin-polarized alternating currents and anisotropic magnetoresistance measurements yield discreet frequencies from a single device. Indeed, chromium-implanted regions of permalloy disks exhibit different saturation magnetisation than neighbouring, non-irradiated areas, and thus different resonance frequency, corresponding to the specific area where the core is gyrating. Our study proves that such devices can be fabricated without the need of further lithographical steps, suggesting ion irradiation can be a viable and costeffective fabrication method for densely-packed networks of oscillators. This material is available free of charge via the Internet at http://pubs.acs.org.

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“…Despite extensive research into the magnetic behaviour of nanodots [12,[15][16][17], coupleddot structures have received less attention. In a recent work, Durowade and Metlushko conducted micromagnetic simulations of touching circular nanodots [18].…”

Section: Introductionmentioning

confidence: 99%

In plane magnetization reversal in nanosized thin truncated conical double-disks of permalloy

Sahu¹,

Tandon²,

Mishra³

2022

Modelling Simul. Mater. Sci. Eng.

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In plane magnetization reversal of permalloy thin truncated conical double-disk as a function of the σ = r/R is investigated using micromagnetic simulations with fixed base radius (R) of 100 nm. When external magnetic field is applied along the longer axis of the double-disk, the remanent states change gradually from vortex state to S state and then to buckled magnetization state with reduction of σ. When σ ≈ 1 and the conical nanodisk resembles to a regular cylindrical nanodisk, incoherent magnetization reversal is dominant whereas tapering of conical disk reduces extent of incoherence in magnetization reversal. As tapering of nanodisk goes extreme so that σ ≈ 0.1, the magnetization reversal is governed only by coherent rotation. Correspondingly, coercive field reduces monotonically as σ increases. On the other hand, when a field is applied in plane but perpendicular to the long axis, almost zero coercivity is discovered. These variations are explained using a analytical calculation of demagnetization factors which quantifies shape anisotropy as well as the consideration of incoherence in magnetization reversal.

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Spin Vortex Resonance in Non-planar Ferromagnetic Dots

Cited by 6 publications

References 23 publications

Collective magnetization dynamics in nanoarrays of thin FePd disks

Collective magnetization dynamics in nanoarrays of thin FePd disks

Tunable Magnetic Vortex Dynamics in Ion-Implanted Permalloy Disks

In plane magnetization reversal in nanosized thin truncated conical double-disks of permalloy

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