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# IEEE Magnetics Letters

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Displaying Results 1 - 25 of 32
• ### Front Cover

Publication Year: 2014, Article Sequence Number: 0000101
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• ### IEEE Magnetics Society Information

Publication Year: 2014, Article Sequence Number: 0000201
| PDF (67 KB)
• ### IEEE Magnetics Letters Publication Information

Publication Year: 2014, Article Sequence Number: 0000301
| PDF (218 KB)

Publication Year: 2014, Article Sequence Number: 0000401
| PDF (330 KB)

Publication Year: 2014, Article Sequence Number: 0100102
| PDF (124 KB)
• ### High-Thrust Linear Actuator Based on Double Corner-Pole Airgaps for Proportional Relief Valve

Publication Year: 2014, Article Sequence Number: 0800104
| | PDF (661 KB)

This letter presents a high-thrust linear actuator for use in a proportional relief valve, based on double corner-pole airgaps formed by the structure of welding sleeve and step armature. The magnetic flux through the double corner-pole airgaps are divided into three parts of two radial fluxes (Φ1, Φ3) and one axial flux (Φ2), resulting in a linear characteristic with high-thr... View full abstract»

• ### Atmospheric Magnetic Noise Measurements in Urban Areas

Publication Year: 2014, Article Sequence Number: 0800204
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The theory of atmospheric magnetic noise is reviewed and we discuss how it impacts magnetoinductive communications systems. Magnetic noise measurements are then conducted to obtain quantitative values of the noise levels at both indoor and outdoor locations. The measurements, using an industrial-grade magnetometer, are compared with results from Comité Consultatif International des Radioco... View full abstract»

• ### General Solution of the Hollow Cylinder and Concentric DC Surface Current

Publication Year: 2014, Article Sequence Number: 0800304
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We provide a general solution to the problem of an infinitely long, hollow cylinder of uniform, linear permeability in the presence of any continuous dc current distribution residing on a concentric cylindrical surface. The solution is expressed in terms of the spatial Fourier components of the applied surface current. Applications of this study include the design of dc magnetic shields and shield... View full abstract»

• ### Optimization of Force Between Cylindrical Permanent Magnets

Publication Year: 2014, Article Sequence Number: 0800404
Cited by:  Papers (1)
| | PDF (425 KB) | HTML

We calculated analytically and with the finite-element method the force between two identical coaxial cylindrical magnets for nine different magnetic materials at separations of 1, 3, 5, 7, and 9 mm and for height-to-diameter ratios between 0.1 and 2. For the analytical calculations, we assumed homogeneous magnetization. For the nonhomogeneous case, we used the finite-element method taking into co... View full abstract»

• ### Strength of Perpendicular Magnetic Anisotropy at Bottom and Top Interfaces in [Pt/Co/Pt] Trilayers

Publication Year: 2014, Article Sequence Number: 1000104
Cited by:  Papers (1)
| | PDF (549 KB) | HTML

The individual strengths of perpendicular magnetic anisotropy (PMA) at the bottom and top interfaces in sputtered [Pt/Co/Pt] trilayers are determined. The PMA strength from the top Co/Pt interface is significantly weaker than that from the bottom Pt/Co interface, indicating a similar difference in the interface quality. The contribution to the total anisotropy strength from the top Co/Pt interface... View full abstract»

• ### Transcranial Magnetic Stimulation Device With Reduced Acoustic Noise

Publication Year: 2014, Article Sequence Number: 1500104
Cited by:  Papers (4)
| | PDF (265 KB) | HTML Media

Transcranial magnetic stimulation (TMS) is widely used for noninvasive activation of neurons in the brain for research and clinical applications. The strong, brief magnetic pulse generated in TMS is associated with a loud (>100 dB) clicking sound that can impair hearing and that activates auditory circuits in the brain. We introduce a two-pronged solution to reduce TMS noise by redesigning both... View full abstract»

• ### Magneto-Electric Control of Surface Anisotropy and Nucleation Modes in L1 $_{0}$-CoPt Thin Films

Publication Year: 2014, Article Sequence Number: 2500104
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The interplay between electric field-controlled surface magnetic anisotropy and micromagnetic nucleation modes for L10-CoPt thin films is investigated with density-functional and micromagnetic model calculations. The electric field redistributes electron states near the Fermi level, which has a fairly strong effect on the surface anisotropy, but due to inversion symmetry, the net anisot... View full abstract»

• ### Self-Modulated Soliton Modes Excited in a Nanocontact Spin-Torque Oscillator

Publication Year: 2014, Article Sequence Number: 3000104
Cited by:  Papers (17)
| | PDF (320 KB) | HTML

Self-modulated bubble-like solitons, namely droplets, recently observed in spin-torque nanooscillators with a perpendicular free layer, are promising for applications in spintronics, magnonics, and magnetic logic devices. This letter presents a micromagnetic analysis on soliton dynamics. Our results identify the role of physical parameters (i.e., external field, saturation magnetization, and excha... View full abstract»

• ### Linewidth Variation of the Higher Harmonics in Spin-Torque Vortex Oscillators

Publication Year: 2014, Article Sequence Number: 3000204
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We have studied microwave emission due to vortex gyration in pseudo-spin-valve nanopillar devices. Subgigahertz emission spectra with a large number of higher harmonics are found with linewidth of the fundamental peak as low as ~500 kHz. Several distinct gyration modes exist whose peak frequencies are separated by a few tens of megahertz, likely corresponding to magnetic oscillations with differen... View full abstract»

• ### Microwave Properties and Damping in [Pt/Co] Multilayers With Perpendicular Anisotropy

Publication Year: 2014, Article Sequence Number: 3000304
Cited by:  Papers (1)
| | PDF (373 KB) | HTML

Magnetic tunnel junctions with perpendicularly magnetized elements are being considered for next-generation, non-volatile, magnetic random access memory (MRAM) elements due to their large thermal stability, low Gilbert damping constant α, and very low critical current density Jc required for spin-transfer-torque (STT), current-induced, magnetization switching. Here we study, by means of sta... View full abstract»

• Spin Electronics
• ### Effect of Excitation Fatigue on the Synchronization of Multiple Nanocontact Spin-Torque Oscillators

Publication Year: 2014, Article Sequence Number: 3000404
Cited by:  Papers (2)
| | PDF (306 KB) | HTML

Nanocontact spin-torque oscillators (NC-STOs) act as intrinsically nanoscale and highly current and magnetic field tunable, ultrawide band microwave signal generators. However, their low output power and high phase noise remain critical obstacles toward actual applications. Mutual synchronization of multiple NCs is one possibility to overcome these shortcomings. This letter presents a detailed stu... View full abstract»

• ### CoFeB-Based Spin Hall Nano-Oscillators

Publication Year: 2014, Article Sequence Number: 3000504
Cited by:  Papers (18)
| | PDF (337 KB) | HTML

We demonstrate magnetization auto-oscillations driven by pure spin currents in spin Hall nano-oscillators based on CoFeB/Pt bilayers. Despite the very low anisotropic magnetoresistance of CoFeB, a substantial microwave signal power can be detected, even at room temperature, indicating that a sizable spin wave amplitude is generated. Spin torque ferromagnetic resonance measurements reveal that the ... View full abstract»

• ### Strong Eddy-Current Shielding of Ferromagnetic Resonance Response in Sub-Skin-Depth-Thick Conducting Magnetic Multilayers

Publication Year: 2014, Article Sequence Number: 3500104
Cited by:  Papers (6)
| | PDF (263 KB) | HTML

Exchange-coupled nonmagnetic metal (NM) and ferromagnetic metal (FM) multilayers are crucial for microwave magnonic and spintronic devices. These layered materials usually have total thicknesses smaller than the microwave skin depth. By using a stripline broadband ferromagnetic resonance spectroscopy technique, we experimentally demonstrate that the amplitude of the magnetization precession in the... View full abstract»

• ### Detection of the DC Inverse Spin Hall Effect Due to Spin Pumping in a Novel Meander-Stripline Geometry

Publication Year: 2014, Article Sequence Number: 3700104
Cited by:  Papers (7)
| | PDF (664 KB) | HTML

The dc voltage obtained from the inverse spin Hall effect (iSHE) due to spin pumping in ferromagnet/normal-metal (NM) bilayers can be unintentionally superimposed with magnetoresistive rectification of ac charge currents in the ferromagnetic layer. We introduce a meander-stripline device in which these spurious rectification voltages vanish while the iSHE voltage is maximized. In this device, a qu... View full abstract»

• Microwave Magnetics
• ### Multimode Propagation of Magnetostatic Waves in a Width-Modulated Yttrium-Iron-Garnet Waveguide

Publication Year: 2014, Article Sequence Number: 3700204
Cited by:  Papers (18)
| | PDF (352 KB) | HTML

An irregular tapered ferrite waveguide with a periodically width-modulated region was investigated. By using space- and time-resolved Brillouin light scattering spectroscopy, we measured the features of the intermodal interaction of width modes and their scattering at the boundaries of the waveguide. Near the band-gap frequency region, the spatial pattern of the spin-waves depends on the mode inte... View full abstract»

• ### Ultrahigh Sensitivity Ferromagnetic Resonance Measurement Based on Microwave Interferometer

Publication Year: 2014, Article Sequence Number: 3700304
Cited by:  Papers (6)
| | PDF (302 KB) | HTML

An ultrahigh sensitivity ferromagnetic resonance (FMR) measurement technique based on a microwave interferometer was developed. A comparison between conventional and interferometer-based FMR showed a signal-to-noise ratio (SNR) improvement of as much as 42 dB. This largely improved SNR allowed clear resolution of the FMR signal of the uniform mode on a 100 nm diameter, 5 nm thick CoFeB single nano... View full abstract»

• ### Control of In-Plane Uniaxial Anisotropy of CoPd-CaF $_{2}$ Nanogranular Films by Tandem-Sputtering Deposition

Publication Year: 2014, Article Sequence Number: 3700404
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In-plane uniaxial anisotropic CoPd-CaF2 nanogranular soft magnetic films for gigahertz applications were prepared using RF tandem-sputtering deposition with substrate revolution. Strong anisotropy with a large anisotropy field exceeding 50 kA/m was achieved in the centrifugal-centripetal direction of the substrate revolution, regardless of the presence or absence of an applied external ... View full abstract»

• ### Comparative Study of Magnetic Properties of Nanoparticles by High-Frequency Heat Dissipation and Conventional Magnetometry

Publication Year: 2014, Article Sequence Number: 4000104
Cited by:  Papers (1)
| | PDF (445 KB) | HTML

The rate of heating of 15 nm uniformly-sized magnetic aqueous nanoparticles suspension by high-amplitude and high-frequency ac magnetic field induced by the resonating LC circuit was measured. The results are analyzed in terms of specific energy absorption rate (SAR). Fitting field amplitude and frequency dependences of SAR to the linear response theory, magnetic moment per particles was extracted... View full abstract»

• ### Role of Thermal Effects on Magnetic Interactions in Stacked Magnetic Layers With Perpendicular Anisotropy

Publication Year: 2014, Article Sequence Number: 4500104
| | PDF (347 KB) | HTML

The role of thermally excited magnetization reversals on magnetic interactions in stacked magnetic layers with perpendicular anisotropy has been investigated by first-order reversal curves (FORC) and coercive squareness (S*). For this purpose, a study of the effect of systematic variation of exchange interaction in granular perpendicular magnetic anisotropy layers on FORC contours has been carried... View full abstract»

• ### Coercivity Reduction in Nickel Ferrite (NiFe$_{2}$O $_{4}$) Thin Films Through Surface Patterning

Publication Year: 2014, Article Sequence Number: 5000104
Cited by:  Papers (5)
| | PDF (520 KB) | HTML

NiFe2O4(NFO), a spinel ferrite with high electrical resistivity and favorable magnetic properties, is an interesting material for high-frequency signal and power electronic applications. Here, significant reduction in the coercivity of NFO films is obtained through surface patterning via nanoimprint lithography. Multilayered NFO films are grown on c-plane (0001) sapphire subs... View full abstract»

## Aims & Scope

IEEE Magnetics Letters is a peer-reviewed, archival journal covering the physics and engineering of magnetism, magnetic materials, applied magnetics, design and application of magnetic devices, bio-magnetics, magneto-electronics, and spin electronics.

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## Meet Our Editors

Editor
Ron B. Goldfarb
National Institute of Standards and Technology