Magnetic Microstructure of Rolled‐Up Single‐Layer Ferromagnetic Nanomembranes

Streubel, Robert; Lee, Je-Hyun; Makarov, Denys; Im, Maesoon; Karnaushenko, Daniil; Han, Luyang; Schäfer, Rudolf; Fischer, Peter; Kim, Sang Koog; Schmidt, Oliver G.

doi:10.1002/adma.201303003

Cited by 83 publications

(94 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Ref. [27] the authors simulated the contrast in the shadow of a rolled tube. However, it was based on an analytical form for the distribution of magnetization in a thin sheet, not a simulated micromagnetic configuration.…”

Section: Arxiv:150602866v2 [Cond-matmtrl-sci] 23 Sep 2015mentioning

confidence: 99%

“…These domain walls have been predicted to be liable to reach high and robust velocities [21], due to their specific topology providing them with a protection against transformations [25]. While domains in tubes [26,27] and conventional transverse walls in wires [28] had been imaged, recently some of us provided the experimental proof of the existence of…”

mentioning

confidence: 99%

“…These domain walls have been predicted to be liable to reach high and robust velocities [21], due to their specific topology providing them with a protection against transformations [25]. While domains in tubes [26,27] Let us review again the above-mentioned microscopy techniques, in the light of 3D imaging. SPLEEM and SEMPA typically probe the topmost atomic layer of matter.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Quantitative analysis of shadow x-ray magnetic circular dichroism photoemission electron microscopy

et al. 2015

View full text Add to dashboard Cite

Shadow X-ray Magnetic Circular Dichroism Photo-Emission Electron Microscopy (XMCD-PEEM) is a recent technique, in which the photon intensity in the shadow of an object lying on a surface, may be used to gather information about the three-dimensional magnetization texture inside the object. Our purpose here is to lay the basis of a quantitative analysis of this technique. We first discuss the principle and implementation of a method to simulate the contrast expected from an arbitrary micromagnetic state. Text book examples and successful comparison with experiments are then given. Instrumental settings are finally discussed, having an impact on the contrast and spatial resolution : photon energy, microscope extraction voltage and plane of focus, microscope background level, electric-field related distortion of three-dimensional objects, Fresnel diffraction or photon scattering.Progress is continuous in the decreasing size and increasing complexity of nanosized magnetic systems being designed for either fundamental science or devices. Magnetic microscopies are crucial tools to monitor and understand the properties of such systems. Various types of information are desirable to gather, leading to multiple criteria to classify microscopies: spatial and time resolution, compatibility with environmental parameters such as variable temperature and applied magnetic field, requirements on the sample preparation and compatibility for ex-situ processing such as lithography, correlation with structural information, elemental sensitivity, quantity measured (magnetization, induction, stray field etc.), sensitivity. The most common magnetic microscopies offering spatial resolution below 50 nm and direct sensitivity to magnetization are X-ray Magnetic Circular Dichroism PhotoEmission Electron Microscopy (XMCD-PEEM) [ [7][8][9].Yet another criterion is the volume of the sample probed. This criterium is gaining in importance in the context of the emergence of three-dimensional (3D) magnetic objects and textures. The distribution of magnetization may be truly 3D if along the three directions in space the size of a system lies above magnetic characteristic length scales, such as the dipolar exchange length ∆ d for soft magnetic materials, or the anisotropy exchange length ∆ u for a hard magnetic material [10]. While this is obviously fulfilled in macroscopic materials, the complexity of magnetic textures is such that it cannot be measured in detail, and besides it cannot be controlled to achieve specific functions. The progress in nanofabrication techniques now allows to design suitable systems, both with top-down and bottom-up approaches. Let us give some examples. Flat magnetic elements are basic building blocks in spintronics, being patterned with great 2D versatility with thin film and lithography technologies. Large lateral dimensions may give rise to 2D magnetic textures, such as the so-called vortex state in disks [11]. Such textures are being investigated to design RF oscillator components, relying on the gyrotropic motion ...

show abstract

Section: Arxiv:150602866v2 [Cond-matmtrl-sci] 23 Sep 2015mentioning

confidence: 99%

mentioning

confidence: 99%

“…These domain walls have been predicted to be liable to reach high and robust velocities [21], due to their specific topology providing them with a protection against transformations [25]. While domains in tubes [26,27] Let us review again the above-mentioned microscopy techniques, in the light of 3D imaging. SPLEEM and SEMPA typically probe the topmost atomic layer of matter.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Quantitative analysis of shadow x-ray magnetic circular dichroism photoemission electron microscopy

et al. 2015

View full text Add to dashboard Cite

show abstract

“…This possibility may open up a direction to tailor the interfacial magnetic anisotropy in thin ferromagnetic films without any additional layers of heavy metal, which, in turn, may lead to simpler and cheaper ways to engineer systems with any given anisotropy. Nowadays, the curvature effects in thin magnetic films are becoming more accessible due to experimental advances in flexible electronics [23][24][25][26][27], making the proposed method to control the anisotropy experimentally viable in the near future. Moreover, our findings suggest that similar effects might be observed in thin films with significant surface roughness.…”

mentioning

confidence: 99%

Engineering Curvature-Induced Anisotropy in Thin Ferromagnetic Films

et al. 2017

View full text Add to dashboard Cite

We investigate the effect of large curvature and dipolar energy in thin ferromagnetic films with periodically modulated top and bottom surfaces on magnetization behavior. We predict that the dipolar interaction and surface curvature can produce perpendicular anisotropy which can be controlled by engineering special types of periodic surface structures. Similar effects can be achieved by a significant surface roughness in the film. We demonstrate that, in general, the anisotropy can point in an arbitrary direction depending on the surface curvature. Furthermore, we provide simple examples of these periodic surface structures to show how to engineer particular anisotropies in thin films.

show abstract

“…However, magnetic tomography with x-ray microscopes will enable not only to achieve structural information, but add quantitative information and maybe reveal the spin dynamics in 3dim as well. First steps into this direction are rolledup magnetic thin films [42], which can be fabricated by strain engineering and exhibit an increased magneto-resistance which scales with the winding number of the films [43]. Such systems can be seen as prototypes for a shapeable spintronics in analogy to shapeable electronics [44].…”

Section: What Has Been Achieved So Far With Magnetic X-ray Microscopimentioning

confidence: 99%

Frontiers in imaging magnetism with polarized x-rays

Fischer

2015

Front. Phys.

Self Cite

View full text Add to dashboard Cite

Although magnetic imaging with polarized x-rays is a rather young scientific discipline, the various types of established x-ray microscopes have already taken an important role in state-of-the-art characterization of the properties and behavior of spin textures in advanced materials. The opportunities ahead will be to obtain in a unique way indispensable multidimensional information of the structure, dynamics and composition of scientifically interesting and technologically relevant magnetic materials.Keywords: X-ray spectromicroscopy, Fresnel zone plates, spin dynamics, nanomagnetism, x-ray magnetic circular dichroism Although magnetism is among the oldest physical phenomena known to mankind, the magnetic properties of condensed matter continue to be among the most exciting scientific topics in solid state physics. Magnetism is the backbone of numerous current and future technologies having penetrated our daily life. Applications involving magnetic materials range from nanoscale devices in spintronics [1] that have revolutionized information and sensor technologies to large permanent magnets [2] critical to power generation, transmission and conversion and transportation, e.g., with electric vehicles. Despite this massive technological use of magnetic materials, a fundamental understanding of magnetism, which would allow predicting e.g., a lightweight, sustainable and high performing material for permanent magnets, is still missing.From the scientific point of view, it is the spin of the electron and the coupling and competing interactions of all spins in a system, which constitutes the fundamental theoretical concept to describe magnetism and magnetic behavior. The exchange interaction is the strongest interaction and favors either parallel or antiparallel alignment of the spins thus giving rise to ferroor antiferromagnetism. The spin-orbit interaction is currently a topic of paramount current interest to the magnetism community, specifically as novel effects occur, when e.g., 3d transition metals such as Fe, Co, Ni are interfaced with high Z materials, e.g., Pt, Ta, thus adding a large spin-orbit coupling. Chiral interactions, such as the Dzyaloshinkii-Moriya interaction, favor non-collinear spin arrangements, and introduces e.g., a certain handedness, which not only gives rise to topologically protected spin textures such as skyrmions, but impacts also, e.g., domain wall motion in nanowires [3].The magnetic anisotropy prefers certain orientation of the spins and therefore ultimately enables concepts e.g., to store magnetic information. One of the problems in magnetic recording is that higher anisotropy magnetic materials are needed to increase thermal stability. On the other hand, a higher anisotropy requires increased magnetic fields for magnetization reversal, which has engineering limitations. The most promising path to bypass this trilemma is heat assisted magnetic recording [4], where temporarily the anisotropy is locally reduced by heating thus allowing for switching locally the magnetization with much...

show abstract

Magnetic Microstructure of Rolled‐Up Single‐Layer Ferromagnetic Nanomembranes

Cited by 83 publications

References 45 publications

Quantitative analysis of shadow x-ray magnetic circular dichroism photoemission electron microscopy

Quantitative analysis of shadow x-ray magnetic circular dichroism photoemission electron microscopy

Engineering Curvature-Induced Anisotropy in Thin Ferromagnetic Films

Frontiers in imaging magnetism with polarized x-rays

Contact Info

Product

Resources

About