Magnetic stripe domains in ultrathin films and their transformation in magnetic fields

By combining Brillouin Light Scattering and micromagnetic simulations we studied the spin-wave dynamics of a Co/Pd thin film multilayer, features a stripe domain structure at remanence. The periodic up and down domains are separated by cork-screw type domain walls. The existence of these domains causes a scattering of the otherwise bulk and surface spin-wave modes, which form mode families, similar to a one dimensional magnonic crystal. The dispersion relation and mode profiles of spin waves are measured for transferred wave vector parallel and perpendicular to the domain axis.The possibility to use spin-waves (SW) to excite, transmit, store, and retrieve electric signals as well as to perform logical operations has fueled a new spectrum of research in the wavebased signal processing technology [1-4]. Usually, magnonic crystals (MC), i.e. arrays of macroscopic magnetic stripes [5], dots [6], antidots [7], etched grooves or pits[1], periodic variations of the internal magnetic field [9] and saturation magnetization by ion implantation [10], are employed to control the flow of SWs. Magnetostatic surface SWs or the Damon-Eshbach (DE) SW modes, which propagate perpendicular to the in-plane (IP) magnetization direction, are promising in this context because of their large group velocities (vg) and low attenuation.Consequently, significant progress has been made towards the practical realization of magnonic devices in terms of the on-chip generation, directional channeling, detection and manipulation of SWs. However, to realize the experimental geometry, a large magnetic field has to be applied to enforce the magnetization perpendicular to the SW propagation direction. This is a major obstacle to the implementation of a MC into a practical device. A way out is to use the Oersted field generated from an underlying current-carrying stripe [11][12], which is still plagued by the problem of generation of waste heat which increases with increasing data processing speed. Moreover, the fabrication of periodic nanostructures involves high-precision electron-beam lithography which is very complex and expensive. An alternative approach to overcome these fundamental drawbacks is to take recourse to the spin dynamics in the remanent state, which is more suitable for nanoscale device applications, as it does not require any stand-by power once initialized.In the literature, only few reports exist on the magnetization dynamics for systems with an inhomogeneous magnetization distribution containing domains and domain walls. Most commonly studied is a periodic or non-periodic distribution of magnetic units of up and down domains (parallel, labyrinthine, bubble-like domains) [13][14][15][16][17][18][19], separated by negligibly thin, onedimensional domain walls. Such domains appear in magnetic thin films with a perpendicular anisotropy smaller than the demagnetizing energy if the film thickness is higher than a critical value tc, which is, in turn, dependent on the perpendicular anisotropy constant, saturation magnetization and the exc...

show abstract

“…FePd [48] [7], Fe/Cu [49], Co/Cu/(Fe/Ni)/Cu(001) [50]and Co/Au [51] multilayers. However, the dynamic SW properties are still unexplored.…”

mentioning

confidence: 99%

Magnonic band structure in a Co/Pd stripe domain system investigated by Brillouin light scattering and micromagnetic simulations

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This is also important as the smallest of ground state stripe widths seen experimentally is still quite large, typically on the order of 100-1000 spins. [27,28] Thus h = 8 must be considered small when comparing to experimental system, however it is hoped that scaling arguments can be developed which will allow meaningful comparisons to be made. [29] To study the dynamics and more precisely the late stage relaxation of this system we need to be able to define domains within the system which are based, not on the state of the spins, but on the local orientation of the stripes.…”

Section: Previous Workmentioning

confidence: 99%

Late stage, non-equilibrium dynamics in the dipolar Ising model

Hosiawa¹,

MacIsaac²

2009

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

Magnetic domain structures are a fascinating area of study with interest deriving both from technological applications and fundamental scientific questions. The nature of the striped magnetic phases observed in ultra-thin films is one such intriguing system. The non-equilibrium dynamics of such systems as they evolve toward equilibrium has only recently become an area of interest and previous work on model systems showed evidence of complex, slow dynamics with glass-like properties as the stripes order mesoscopically. To aid in the characterization of the observed phases and the nature of the transitions observed in model systems we have developed an efficient method for identifying clusters or domains in the spin system, where the clusters are based on the stripe orientation. Thus we are able to track the growth and decay of such clusters of stripes in a Monte Carlo simulation and observe directly the nature of the slow dynamics. We have applied this method to consider the growth and decay of ordered domains after a quench from a saturated magnetic state to temperatures near and well below the critical temperature in the two dimensional dipolar Ising model. We discuss our method of identifying stripe domains or clusters of stripes within this model and present the results of our investigations.

show abstract

“…A variety of interesting properties have been observed in magnetic ultrathin films [1][2][3][4][5][6][7][8]. It is motivated to a large extent by industrial importance of these films due to possible applications [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Analysis of checkerboard pattern in ultrathin magnetic films

Kaplan

2006

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

Magnetic stripe domains in ultrathin films and their transformation in magnetic fields

Cited by 4 publications

References 10 publications

Magnonic band structure in a Co/Pd stripe domain system investigated by Brillouin light scattering and micromagnetic simulations

Magnonic band structure in a Co/Pd stripe domain system investigated by Brillouin light scattering and micromagnetic simulations

Late stage, non-equilibrium dynamics in the dipolar Ising model

Analysis of checkerboard pattern in ultrathin magnetic films

Contact Info

Product

Resources

About