Magnetic Patterns Research Articles

Magnetic and geometric control of spin textures in the itinerant kagome magnet Fe3Sn2

Magnetic materials with competing magnetocrystalline anisotropy and dipolar energies can develop a wide range of domain patterns, including classical stripe domains, domain branching, and topologically trivial and nontrivial (skyrmionic) bubbles. We image the magnetic domain pattern of ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ by magnetic force microscopy and study its evolution due to geometrical confinement, magnetic fields, and their combination. In ${\mathrm{Fe}}_{3}{\mathrm{Sn}}_{2}$ lamellae thinner than 3 $\ensuremath{\mu}\mathrm{m}$, we observe stripe domains whose size scales with the square root of the lamella thickness, exhibiting classical Kittel scaling. Magnetic fields turn these stripes into a highly disordered bubble lattice. Complementary micromagnetic simulations quantitatively capture the magnetic field and thickness dependence of the magnetic patterns, reveal strong reconstructions of the patterns between the surface and the core of the lamellae, and identify the observed bubbles as skyrmionic bubbles. Our results imply that geometrical confinement together with competing magnetic interactions can provide a path to fine-tune and stabilize different types of topologically trivial and nontrivial spin structures in centrosymmetric magnets.

Imaging patterns in pediatric hypophosphatasia.

Hypophosphatasia is a rare genetic disorder of calcium and phosphate metabolism due to ALPL gene mutations, which leads to abnormal mineralization of the bones and teeth. Hypophosphatasia is characterized by low serum alkaline phosphatase activity and a number of clinical signs, including failure to thrive, bone pain and dental issues. The diagnosis is suspected based on clinical, laboratory and imaging findings and confirmed by genetic testing. Diagnosis in children is often delayed due to a lack of disease awareness, despite specific imaging findings that are a cornerstone of the diagnosis. The recent approval of enzyme replacement therapy (bone-targeted recombinant tissue nonspecific alkaline phosphatase) has given imaging an important role in monitoring treatment efficacy. The aim of this pictorial essay is to review the imaging features of hypophosphatasia at diagnosis and during follow-up, including whole-body magnetic resonance imaging patterns.

Analyzing the Intrinsic Magnetic Field in the Galactic Center Radio Arc

Abstract The Radio Arc is a system of organized nonthermal filaments (NTFs) located within the Galactic center (GC) region of the Milky Way. Recent observations of the Radio Arc NTFs revealed a magnetic field that alternates between being parallel and rotated with respect to the orientation of the filaments. This pattern is in stark contrast to the predominantly parallel magnetic field orientations observed in other GC NTFs. To help elucidate the origin of this pattern, we analyze spectro-polarimetric data of the Radio Arc NTFs using an Australian Telescope Compact Array data set covering the continuous frequency range from ∼4 to 11 GHz at a spectral resolution of 2 MHz. We fit depolarization models to the spectral polarization data to characterize Faraday effects along the line of sight. We assess whether structures local to the Radio Arc NTFs may contribute to the unusual magnetic field orientation. External Faraday effects are identified as the most likely origin of the rotation observed for the Radio Arc NTFs; however, internal Faraday effects are also found to be likely in regions of parallel magnetic field. The increased likelihood of internal Faraday effects in parallel magnetic field regions may be attributed to the effects of structures local to the GC. One such structure could be the Radio Shell local to the Radio Arc NTFs. Future studies are needed to determine whether this alternating magnetic field pattern is present in other multi-stranded NTFs, or is a unique property resulting from the complex interstellar region local to the Radio Arc NTFs.

Static and dynamic properties of 1-kink skyrmion in Pt/Co/MgO trilayer

The 1-kink skyrmion is a topological spin texture composed of a skyrmion having a chiral kink inside its N\'eel domain wall, this chiral kink being also called domain wall skyrmion. By micromagnetic simulations we have studied the stability of the 1-kink skyrmion as well as its spin-driven dynamics in Pt/Co/MgO. Such trilayer system allows simultaneously the stabilization of various spin textures including skyrmion (Sk, topological charge $Q=1$), 1-kink skyrmion (1kSk, $Q=2$), and domain wall skyrmion (DWSk, $Q=1$). The 1-kink skyrmion is found to be robust against both thermal fluctuations and normally distributed anisotropy for different grainlike region sizes. Such magnetization pattern has a certain resilience to the variation of the Dzyaloshinskii-Moriya interaction and applied magnetic field. The static analysis is complemented with the investigation of the dynamic regime of motion under electrical current. In the limit of moderate injected current the skyrmion and the 1-kink skyrmion behave similarly. However, depending on the geometry of the injected current, the 1-kink skyrmion can be transformed into a single skyrmion or splits in two skyrmions, opening the path to conceive high density logical devices, enabling novel functionalities for logic operations.

Mesozoic dike swarms in Borborema Province (NE Brazil): A structural analysis based on airborne geophysical data and field work

Mapping and analysis of dike swarms support a detailed understanding of the orientation, geometry, spatial distribution, geochronology, emplacement mechanism, structural control, and environments at the time of the magmatic events. Therefore, dike swarms have become a key tool for studying mantle plume activity, large igneous provinces, and continental breakup. Before the Pangea breakup, the Neoproterozoic Borborema Province (NE Brazil) was intensively intruded by sets of dike swarms, whose precise mapping and classification are essential for understanding the tectonic plate movements and evolution of the South American and African continents. In this sense, we promoted a regional mapping of dike swarms and their relationships between orientation, emplacement mechanism and structural control to provide a better understanding of the role of Mesozoic and Cenozoic large magmatic events in their tectonic evolution. We apply anomaly enhancement techniques to high-resolution airborne magnetic data to obtain the geometry and estimate the depth of causative sources. A structural analysis was carried out integrating magnetic patterns, field data and a compilation of previous geological maps to describe the detailed distribution of dike swarms in Borborema Province. Our study demonstrated that dike swarms extend over 5.4 × 105 km2. The 1388 mapped mafic dikes are grouped into three distinct dike swarms (DS): 1135 – Rio Ceará-Mirim DS; 168 – Canindé DS; and 85 – Riacho do Cordeiro DS. The dike swarms show three preferential trends: NE-SW, E-W and NW-SE. The geometry and structural analysis of the dikes allowed us to establish the paleostress field active at the time of intrusion. For the Rio Ceará-Mirim DS, the paleostress trajectories represent an N–S extension, rotating to NW-SE in the western portion of the swarm. For the Canindé DS, the paleostress orientation shows a NW-SE extension rotating to NE-SW. For the Riacho do Cordeiro DS, the trajectories are similar to those traced for the Rio Ceará-Mirim DS, showing a predominant NW-SE trend.

Structural, electronic and magnetocaloric properties of antiskyrmion hosting Heusler compounds: Mn2PtSn and Mn1.4PtSn

In this work, we have studied the structure, electronic and magnetic properties of Mn2PtSn and Mn1.4PtSn by using the ab initio calculations and Monte Carlo study. The ab initio calculations, based on the functional theory of density combined with the method of linear augmented plane waves at potential, are performed to investigate both electronic and magnetic properties of the two compounds. The total and partial densities of two systems have been calculated. Mn1.4PtSn, the first known Heusler tetragonal (Mn vacancy-induced) superstructure compound, opens a new direction of research for superstructure-related properties in a family containing multiple compounds. We have deduced the total magnetic moment of the two systems. We observe an anisotropic fractal magnetic pattern of zero-field closing domains above the spin-reorientation transition temperature, which transforms into a set of high-field bubble domains. Below the spin-reorientation transition temperature, the strong in-plane anisotropy as well as the zero-field fractal self-affinity is gradually lost, while the formation of high-field bubble domains remains robust. The magnetization, specific heat and magnetic entropy change have been obtained by using the Monte Carlo simulations. The relative cooling power has been obtained for different values of external magnetic field and temperatures.

The effect of cation distribution and heat treatment temperature on the structural, surface, morphological and magnetic properties of MnxCo1−xFe2O4@SiO2 nanocomposites

This paper presents the effect of Mn2+ substitution for Co2+, in CoFe2O4 embedded in SiO2 matrix, on the structural, surface, morphological and magnetic properties. X-ray diffraction (XRD) and Mössbauer spectroscopy indicate the presence of a nanocrystalline mixed cubic spinel. In all cases, for the nanocomposites (NCs) heat-treated at 200 °C, a single, low crystalline ferrite phase was remarked, while for the other heat-treatment temperatures up to 1200 °C and with increasing Mn content, the secondary phase of α-Fe2O3 appears, accompanied also by the secondary phase of SiO2 at 1200 °C. The Fourier transform infrared (FT-IR) spectroscopy confirms the consumption of starting metallic nitrates, the formation of Co-O, Mn-O, Fe-O bonds in ferrites@SiO2 matrix. The Mössbauer spectra show the characteristic magnetic patterns of Co and Mn spinels. According to the atomic force microscopy (AFM) analysis, the particle size increases from 15 to 80 nm with the increase of Mn content. The specific surface area varies in the range 150–450 m2/g due to the substitution of Co2+ ion with Mn2+ ion and decreases with increasing heat treatment temperature, reaching values below 1 m2/g at 1200 °C. All NCs have pores within the mesoporous range, with high dispersion of pores’ sizes. Furthermore, the release of fine nanoparticles in aqueous environment is facilitated by the powders’ mesoporous structure preserved at 200, 500 and 800 °C heat treatment temperatures. The porous network collapse after heat treatment at 1200 °C leads to releasing of bigger nanoparticles, in good agreement with AFM observation. Magnetization, coercivity and anisotropy evolve proportionally with the particle size for the NCs heat-treated at 800 °C (MS = 18.9–36.3 emu/g; MR = 3.05–14.1 emu/g, HC = 31.83–53.2 kA/m, K = 0.378·10−3-1.21·10−3 erg/cm−1) and inverse proportionally for those heat-treated at 1200 °C (MS = 30.7–19.4 emu/g; MR = 11.60–7.20 emu/g, Hc = 127.3–15.9 kA/m, K = 2.45·10−3-0.19·10−3 erg/cm−1). The NCs with high Mn content heat-treated at 1200 °C show superparamagnetic behavior, while those with low Mn content display ferrimagnetic behavior.

Longitudinal Motor Functional Outcomes and Magnetic Resonance Imaging Patterns of Muscle Involvement in Upper Limbs in Duchenne Muscular Dystrophy.

Background and Objectives: The aim of this study was to evaluate longitudinal changes using both upper limb muscle Magnetic Resonance Imaging (MRI) at shoulder, arm and forearm levels and Performance of upper limb (PUL) in ambulant and non-ambulant Duchenne Muscular Dystrophy (DMD) patients. We also wished to define whether baseline muscle MRI could help to predict functional changes after one year. Materials and Methods: Twenty-seven patients had both baseline and 12month muscle MRI and PUL assessments one year later. Results: Ten were ambulant (age range 5–16 years), and 17 non ambulant (age range 10–30 years). Increased abnormalities equal or more than 1.5 point on muscle MRI at follow up were found on all domains: at shoulder level 12/27 patients (44%), at arm level 4/27 (15%) and at forearm level 6/27 (22%). Lower follow up PUL score were found in 8/27 patients (30%) at shoulder level, in 9/27 patients (33%) at mid-level whereas no functional changes were found at distal level. There was no constant association between baseline MRI scores and follow up PUL scores at arm and forearm levels but at shoulder level patients with moderate impairment on the baseline MRI scores between 16 and 34 had the highest risk of decreased function on PUL over a year. Conclusions: Our results confirmed that the integrated use of functional scales and imaging can help to monitor functional and MRI changes over time.

Pemetaan batuan penyusun candi di bawah permukaan berdasarkan metode geomagnetik studi kasus: cagar budaya candi Songgiriti desa Songgokerto kecamatan Batu kota Batu

The geomagnetic method is often used in petroleum, geothermal and mineral exploration and can be applied to searching prospect archaeological objects (Siahaan, 2009). Several studies has been used the geomagnetic method to seek for archaeological objects by Ariani (2012) in Losari Temples and Sismanto et al (1997) in Kedulan Temple. In Batu City there is one of the cultural heritage that have not been intact called Songgoriti Temple. So, in this research we expected the existence of temple’s rocks using geomagnetic method. The de sign of the research using geomagnetic methods begins with the study of litera ture. This research was conducted with two methods there is calculating the val ue of the magnetic susceptibility of samples Temple’s rock using Bartington Susceptibility Meter MS2B and retrieving data field using the Proton magneto meter type ENVI SCINTREX. In the end of this research, we accepted the re sults of the two methods were compared to find out the site rock of temple. In magnetometer data analysis, data is processed using Magpick software, surfer 9.0 software and Mag2dc software. The results of the research show that a local magnetic field patterns of rocks in the area of cultural heritage Songgoriti Tem ple is divided into three parts namely high local magnetic field (yellow to red), the moderate local magnetic field (green to yellow) and low local magnetic field (blue). Furthermore based on five cross-sectional modeling using Mag2dc, we obtained the prediction the site of temple Songgoriti that is the sample number 1 found on the 2 position i.e at coordinates 49S 664547.5m 9130115m and coor dinate 49S 664585m 9130105m; sample number 3 found on the 2 position i.e at coordinates 49S 664583m 9130100m and coordinate 49S 664585m 9130100m; sample number 4 found on the 2 position i.e. at coordinates 49S 664577.5m 9130115m and coordinate 49S 664577.5m 9130110m; sample number 5 found on the 3 position i.e. at coordinates 49S 664566m 9130095m, coordinates 49S 664573m 9130095m and coordinate 49S 664582.5 m 9130095m; sample num ber 6 is found in 5 position i.e. at coordinates 49S 664545.5 m 9130110m, coordinates 49S 664550m 9130110m, coordinates 49S 664546m 9130105m, coordinates 49S 664565m 9130105m and coordinates 49S 664562.5 m 9130100m. For sample number 2 that is not found at all in the five models cross section. This may be caused by the value of the magnetic susceptibility sample number 2 is minor when compared to another samples that is 0.86 x 10-6 m3/kg

Leukoencephalopathy with vanishing white matter caused by <i>EIF2B5</i> gene mutations: a case report

Leukoencephalopathy with vanishing white matter (VWM disease) is a progressive neurodegenerative disease with a specific magnetic resonance pattern characterized by diffuse lesions to the white matter and cystic degeneration. In this article, we report a case VWM disease in a boy with white matter lesions, in whom early onset and neurological symptoms suggested infantile form of the disease. The diagnosis was confirmed by the detection of biallelic mutations c.1688G>A (p.Arg563Gln) and c.1309G>A (p.Val437Met) in the EIF2B5 gene. The c.1309G>A mutation (p.Val437Met) was detected for the first time; it caused the development of severe disease.

Dependence of magnetic domain patterns on plasma-induced differential oxidation of CoPd thin films

We demonstrate the evolution of the micro-patterned magnetic domains in CoPd thin films pretreated with e-beam lithography and O2 plasma. During the days-long oxidation, significantly different behaviors of the patterned magnetic domains under magnetization reversal are observed via magneto-optic Kerr effect microscopy on different days. The evolution of the magnetic behaviors indicate critical changes in the local magnetic anisotropy energies due to the Co oxides that evolve into different oxide forms, which are characterized by micro-area X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. The coercive field of the area pre-exposed to plasma can decrease to a value 10 Oe smaller than that unexposed to plasma, whereas after a longer duration of oxidation the coercive field can instead become larger in the area pre-exposed to plasma than that unexposed, leading to an opposite magnetic pattern. Various forms of oxidation can therefore provide an additional dimension for magnetic-domain engineering to the current conventional lithographies.

Design and implementation of a novel interior permanent magnet bearingless slice motor.

In this paper, we present a bearingless motor with a novel segmented dipole interior permanent magnet (IPM) slice rotor. The segmented dipole IPM rotor contains a unique pattern of interior permanent magnets arranged to generate a dipole air gap flux pattern. The magnets are encapsulated within an electrical steel rotor structure. The stator contains a three-phase, four-pole winding for suspension and a three-phase, two-pole winding for rotation. We present analyses of several candidate rotor designs. The analyses indicate that the segmented dipole IPM rotor achieves a reduced trade-off between force and torque capacity and relatively symmetric force dynamics as compared to prior art designs and alternate topologies. Symmetric and decoupled force dynamics allow a simple force decoupling algorithm to be used. We designed, constructed, and tested a prototype system. We experimentally demonstrate that the prototype system can achieve stable levitation and open-loop rotation.

3D Arrangement of Magnetic Particles in Thin Polymer Films Assisted by Magnetically Patterned Exchange Bias Layer Systems

AbstractThe possibility to arrange and embed magnetic micro‐ and nanoparticles in thin polymer film systems using flat magnetically patterned substrate templates is investigated. In contrast to self‐organized particle rows forming by applying a homogeneous magnetic field, particles adapt to the magnetic field landscape of the substrate's magnetic pattern prior to polymer crosslinking. Crosslinking then fixes the particle positions in the polymer. The process is tested for composites of hydrophobic polydimethylsiloxane (PDMS) and maghemite nanoparticles as well as for hydrophilic polyvinyl alcohol (PVOH) and hydrophilic functionalized, superparamagnetic core–shell microspheres. The substrate template is an exchange bias layer system magnetically patterned into parallel‐stripe domains with in‐plane magnetizations and head‐to‐head/tail‐to‐tail remanent magnetization orientation in adjacent magnetic domains. A high occupancy percentage of magnetic beads on a domain wall as well as anisotropic actuation of the composite is achieved.

Magnetic resonance imaging of the internal auditory meatus for vestibular schwannoma in ENT practice: a retrospective analysis with literature and guidelines review.

Magnetic resonance imaging scans of the internal acoustic meatus are commonly requested in the investigation of audio-vestibular symptoms for potential vestibular schwannoma. There have been multiple studies into protocols for requesting magnetic resonance imaging for vestibular schwannoma, but none have been reported based on UK National Institute for Health and Care Excellence guidelines for investigating audio-vestibular symptoms. This study intended to identify the local magnetic resonance imaging detection rates and patterns of vestibular schwannoma, and to audit the conformity of scan requests with the National Institute for Health and Care Excellence guidelines, with a review of relevant literature. A retrospective analysis of 1300 magnetic resonance imaging scans of the internal acoustic meatus, compared against National Institute for Health and Care Excellence guidelines, was conducted over two years. Sixteen scans were positive for vestibular schwannoma, with a detection rate of 1.23 per cent. All positive cases fit the guidelines; three of these could have been missed using other criteria. A total of 281 requests did not meet the guideline criteria but revealed no positive results, supporting the use of National Institute for Health and Care Excellence guidelines in planning magnetic resonance imaging scans for audio-vestibular symptoms.

Electron scattering by magnetic quantum dot in topological insulator

We consider scattering of electrons by magnetic regions in topological insulators characterized by spin-momentum locking. By using perturbation theory and partial wave summation approaches, we analyze the role of the system parameters in different scattering regimes. We demonstrate that the specific features of spin-momentum locking lead to strong differences in the scattering cross-section compared to the conventional spin-independent scattering of electrons in semiconductors. The features include, e.g., the scattering anisotropy and the unusual energy dependence of the scattering cross-section. These results can be useful for the understanding of the kinetic effects in topological insulators with magnetic disorder and for the design of magnetization patterns for control of coupled spin and charge density dynamics.

Determine Optimal Value of Pole Arc to Pole Pitch Ratio in order to Increasing Average Torque and Decreasing Unbalance Magnetic Force in Hybrid Electrical Vehicle

In this paper, the effects of magnetization patterns on the performance of Hybrid Electrical Vehicle (HEV) are investigated. HEVs have three magnetic field sources: armature winding, permanent magnets, and field winding. To initiate the investigation, the magnetic field distributions produced by these three sources are obtained. By using the magnetic field distributions, the machine is analyzed under no-load and on-load conditions, and the operational indices, such as self and mutual inductance, cogging-, reluctance- and instantaneous torque, and unbalance magnetic force (UMF) in x- and y direction are calculated. Various magnetization patterns are considered to investigate their influences on the performance of the machine. This step was done with Maxwell software. Furthermore, instantaneous torque and magnitude of UMF are expressed in term of pole arc to pole pitch ratio by using artificial intelligence. The optimal of the pole arc to pole pitch ratio to maximize the average of instantaneous torque and minimize the magnitude of UMF by some multi-objective algorithms is also computed. The modeling and optimization are performed by Matlab Software.

Magnetic Patterning of Tissue Spheroids Using Polymer Microcapsules Containing Iron Oxide Nanoparticles.

Magnetic tissue engineering is one of the rapidly emerging and promising directions of tissue engineering and biofabrication where the magnetic field is employed as temporal removal support or scaffold. Iron oxide nanoparticles are used to label living cells and provide the desired magnetic properties. Recently, polymer microcapsules loaded with iron oxide nanoparticles have been proposed as a novel approach to designing magnetic materials with high local concentrations. These microcapsules can be readily internalized and retained intracellularly for a long time in various types of cells. The low cytotoxicity of these microcapsules was previously shown in 2D cell culture. This paper has demonstrated that cells containing these nontoxic nanomaterials can form viable 3D tissue spheroids for the first time. The spheroids retained labeled fluorescent microcapsules with magnetic nanoparticles without a detectable cytotoxic effect. The high concentration of packed nanoparticles inside the microcapsules enables the evident magnetic properties of the labeled spheroids to be maintained. Finally, magnetic spheroids can be effectively used for magnetic patterning and biofabrication of tissue-engineering constructs.

Distinctive Neuroimaging Pattern in Term Newborns With Neonatal Placental Encephalopathy: A Case Series

BackgroundIdentifying antepartum versus intrapartum timing and the cause of neonatal encephalopathy (NE) often remains elusive owing to our limited understanding of the underlying pathophysiological processes and lack of appropriate biomarkers. ObjectivesThis retrospective observational study describes a case series of term newborns with NE who displayed a recognizable magnetic resonance imaging pattern of immediately postnatal brain abnormalities that rapidly evolved toward cavitation. Our aim is to (1) report this neuroimaging pattern, (2) look for placental determinants, and (3) depict the outcome. Design/MethodsThis is a unicentric retrospective case series reporting the clinical, radiological, and laboratory findings of NE associated with a distinctive neuroimaging pattern, that is, immediately postnatal extensive corticosubcortical T2 hyperintensities, followed by rapid corticosubcortical cavitation that does not match the neuroimaging picture of intrapartum hypoxic-ischemic encephalopathy (HIE). ResultsSeven term newborns presented bilateral corticosubcortical hyperintensities that were detected on T2 between day of life (DOL) 1-4, which rapidly evolved toward cystic encephalomalacia, that is, between DOL9 and DOL12. All these newborns presented with moderate/severe NE. The outcome was either neonatal death or quadriplegic cerebral palsy and epilepsy. None of the reported patients fulfilled the criteria of a high likelihood of acute intrapartum hypoxic-ischemic or quadriplegic cerebral palsy. All these newborns were exposed to chronic and/or acute placental inflammation and/or hypoxic-ischemic. ConclusionsTo further define the antepartum causes of NE, early neuroimaging and a placental examination are recommended. Brain T2 hyperintense injuries before DOL4 followed by rapid cavitation before DOL12 might be biomarkers of NE from an antepartum/placental origin.

Nanoscale magnetic field imaging for 2D materials

Nanometer-scale imaging of magnetization and current density is the key to deciphering the mechanisms behind a variety of new and poorly understood condensed matter phenomena. The recently discovered correlated states hosted in atomically layered materials such as twisted bilayer graphene or van der Waals heterostructures are noteworthy examples. Manifestations of these states range from superconductivity, to highly insulating states, to magnetism. Their fragility and susceptibility to spatial inhomogeneities limits their macroscopic manifestation and complicates conventional transport or magnetization measurements, which integrate over an entire sample. In contrast, techniques for imaging weak magnetic field patterns with high spatial resolution overcome inhomogeneity by measuring the local fields produced by magnetization and current density. Already, such imaging techniques have shown the vulnerability of correlated states in twisted bilayer graphene to twist-angle disorder and revealed the complex current flows in quantum Hall edge states. Here, we review the state-of-the-art techniques most amenable to the investigation of such systems, because they combine the highest magnetic field sensitivity with the highest spatial resolution and are minimally invasive: magnetic force microscopy, scanning superconducting quantum interference device microscopy, and scanning nitrogen-vacancy center microscopy. We compare the capabilities of these techniques, their required operating conditions, and assess their suitability to different types of source contrast, in particular magnetization and current density. Finally, we focus on the prospects for improving each technique and speculate on its potential impact, especially in the rapidly growing field of two-dimensional (2D) materials.

Thermally Excited Spin Waves of NiFe Nano-ring Arrays on Anodic Aluminum Oxide Templates

The patterned substrates have been widely developed for various applications in the nanotechnology. In particular, the magnetic ring arrays could be utilized to not only the magnetic devices, such as memories and logics, but also magnetic stealth films using spin wave excitations. In this works, the magnetic switching behaviors and the thermally excited spin wave properties of the NiFe (permalloy) ring arrays on the anodic aluminum oxide template with carbon nanotubes were investigated. With increasing the diameter of the rings, the larger dipole interactions induced the larger coercive field of the array films in the plane directions. At the magnetically saturation conditions, the smaller diameter of the rings produced the single and broad spin wave absorptions due to the isotropic magnetic domains in both the horizontal and the vertical directions. When the size of the ring increased, each component felt different magnetic anisotropy field so that the two spin wave excitation peaks revealed. In terms of the mass production of the magnetic nano-ring arrays on the anodic aluminum oxide template, the various size and the shapes of the magnetic ring patterns could be good candidates for the rf stealth films of the defense industries.