Bit-patterned media recording (BPMR) is one of the most promising candidates to further increase recording density beyond 1 Tb/in 2 . For high-density BPMR systems, severe intertrack interference (ITI) and media noise caused by decreased track pitch bring severe deterioration to the readback signals. To mitigate the impact of ITI and media noise on bit error rate (BER) performance, we developed a multitrack

Molybdenum disulfide (MoS 2 ) is a significant material yet to be explored for its magnetic properties. In this letter, thin films of MoS 2 are grown on n-silicon substrates via a spin coating method. Deposited films are magnetically annealed at 200 °C with a varying magnetic field from 280 to 520 G. Furthermore, the effect of magnetic field annealing on the structural and magnetization properties

In this letter we study magnetization reversal and transformation of magnetic domain structures in glass-covered magnetic microwires. Studies were performed using the magneto-optical Kerr effect technique in the presence of the combination of tension and torsion mechanical stresses. Formation and reversible transformations of the surface helical structure, induced by the combined stress, were found

This letter discusses the temperature dependence of the magnetic field at which irreversible magnetic flux loss of ferrite sintered magnets is initiated. In this material class such a field might reduce linearly: comparable behavior to that observed for Nd-Fe-B-based sintered counterparts increases linearly or even peaks for temperatures above 350 K. These differences are attributed to variations in

We investigated the static and dynamic magnetic properties of Zn 0.4 Fe 2.6 O 4 nanoparticles synthesized by thermal decomposition. Two ranges of diameter were used: small particles (diameter about 6.2 nm) and larger ones (diameter about 22.4 nm). The nanoparticle microstructure was characterized by transmission electron microscopy. The temperature dependence of the zero-field dynamic permeability

We analyze the scalability of a spin–orbit torque random access memory (SOT-MRAM)-based physical unclonable function (PUF) at the nanoscale size by means of a hybrid CMOS/spintronics simulation framework. The properties of the SOT-MRAM device (diameters from 100 nm down to 25 nm) are computed via micromagnetic simulations, whereas their implications for PUF applications are evaluated at the circuit

An analog microwave signal correlator, based on parametric pumping of a spin wave by a radio frequency (RF) magnetic field, is demonstrated. The binary codes to be correlated modulate the two microwave signals input to the device to, respectively, excite the spin wave and RF field at twice the carrier frequency of the spin wave. The magnetic field parametrically pumps the spin wave, generating a counterpropagating

We introduce a formulation of a two-sublattice micromagnetic model, which can describe the statics and dynamics of ferromagnets, antiferromagnets, and ferrimagnets. Such a formulation is based on the normalization of exchange, Dzyaloshinskii–Moriya interaction, and anisotropy parameters with respect to the square modulus of the saturation magnetization for each sublattice. We show a study of the statics

Losses in magnetic circuits are closely related to reluctance. Dealing with coils, transformers, stator poles, rotors in motors, and electromagnets with iron slabs in electrical actuators may raise the question regarding the effect of the slope of section profiles on losses and performance. In this letter, with dc and ac sources, through injective section profiles, we obtain complex, negative, and

Materials such as L 1 0 Fe-based alloys with perpendicular magnetic anisotropy derived from crystal structure have the potential to deliver higher thermal stability of magnetic memory elements compared to materials whose anisotropy is derived from surfaces and interfaces. A number of processing parameters enable control of the quality and texture of L 1 0 FePd; among them are substrate, deposition

We demonstrate a technical solution to achieve an intense 50 Hz alternating magnetic field and a static magnetic field made by a permanent magnet at the same place. A compact coil built using the Bitter coil concept is customized to support alternating current, thus creating an alternating magnetic field. A complementary permanent magnet assembly is built around it to achieve the superposition of both

Track misregistration (TMR) is one of several problems in ultrahigh areal density bit-patterned magnetic recording (BPMR) systems, in which the distances between bit-islands are very narrow in both cross-track and down-track directions. Unfortunately, distance reduction leads to intersymbol interference and intertrack interference (ITI) effects, which cause system performance degradation. To deal with

In this letter, a model of strain-induced nanomagnet at room temperature is established to explore the effect of size error on the reliability of straintronic memory and spin neurons. The results show that the relationship between input voltages and 180° magnetization switching probability (activation function) of the nanomagnet has a size dependence. The slope of the activation function is related

Heat-assisted magnetic recording is a future hard disk drive (HDD) technology for extremely increasing areal density. The tunneling magnetoresistive (TMR) device structure, located inside the magnetic read–write head of a hard drive, is the most complex and sensitive component, which contains sensitive components, such as a touchdown sensor and a near-field transducer. The laser used in the writing

We present an experimental system aimed at mapping the magnetic field created by a ring magnet in the working region of a single-magnet magnetic levitation system. The key idea is based on the photoregistration of a transparent air-filled cavity formed in a thin magnetic fluid layer due to balancing the gas pressure and the pressure emerging due to magnetic forces. As a result, the contour of the magnetic

Recent advances in additive direct-write circuit technology have enabled the fabrication of inductive winding geometries previously considered impossible by conventional methods. In this letter, a winding fabricated around a rectangular cross-section toroidal core is considered. As an extension of research embedding toroidal cores within printed circuit board, this letter considers the minimization

Mercury chalcogenide (Hg 0.865 Mn 0.135 Te) monocrystal was grown by crystallization from a two-phase mixture with replenishment of the melt from a tellurium solution and has n-type conductivity. The electron spin resonance (ESR) spectra of a single crystal were studied before and after X-irradiation. Only one intense anisotropic ESR line was observed at 4.2 K before X-irradiation. The anisotropy parameters

Among magnetic alloys, Alumel (95%Ni-2%Mn-2%Al-1%Si) has been widely used due to its technological applications. We fit the specific heat, at zero magnetic field, of this alloy by the Blume-Capel model for spin $\sigma =1$ on a two- and three-dimensional cubic lattice, using Monte Carlo simulation. The best results obtained on a square lattice (linear dimension $L=512$ and 1000 Monte Carlo steps per

This letter studies the formation of a skyrmion crystal with a noncollinear magneto-electric interaction at the interface between a ferroelectric layer and a magnetic layer with triangular lattice in a ferromagnetic/ferroelectric superlattice and its phase transition. The ground-state spin configuration is calculated by using the steepest descent method. We noted that for zero applied magnetic field

The effect of annealing temperatures on the tunnel magnetoresistance (TMR) of MgO-based magnetic tunnel junctions (MTJs) has been investigated for annealing between 190 and 370°C. The TMR shows a maximum value of 215% at an annealing temperature of 330°C. A strong sensitivity of the TMR and the exchange bias of the pinned ferromagnetic layers on the annealing temperature are observed. Depending on

The Halbach array magnetization of thick-film Nd–Fe–B magnets using local laser irradiation is examined. A 75 µm thick isotropic Nd–Fe–B magnet is deposited on a Si substrate by pulsed laser deposition and used to form microlinear Halbach arrays. The micromagnetization patterning of the Halbach arrays is realized by a combination of pulsed magnetization and laser-assisted heating with changing the

Shingled magnetic recording (SMR) is regarded as the most influential technology for the next-generation magnetic recording systems. The SMR tracks are partly overlapped by each other, and the SMR systems can obtain higher area densities by increasing track per inch density. As a result, this brings more interference from the adjacent sidetracks, i.e., intertrack interference (ITI) while reading the

The various memory applications such as embedded nonvolatile memory, embedded static random-access memory, and standalone dynamic random-access memory have different requirements for the performance of the perpendicular magnetic tunnel junction (pMTJ). However, in conventional pMTJ structures, the write current and stability of the free layer are directly coupled, leading to undesirable tradeoffs in

Mn–Bi alloys modified with Mg and other elements were recently developed into promising rare-earth-free permanent magnets through successive melt spinning, warm compaction, and short magnetic field annealing. This letter reports on the crystal structures, texture, and magnetic properties observed in Mn 50 Bi 49- $x$ Mg $x$ Sb 0.5 In 0.5 alloys ( $x$ = 0, 1.5, 3.0, 4.5) throughout these processing steps

In the practical application of high-temperature superconducting (HTS) magnetic levitation, the influence of ambient temperature on its performance is mainly reflected in the change of magnetic characteristics of the permanent magnet guideway (PMG). In order to investigate the magnetic characteristics of the PMG at high temperature and the influence of temperature on the levitation performance of HTS

The influence of the materials that construct a one-dimensional magnetophotonic crystal (MPC) is investigated in this letter. Recently, we suggested a procedure for realizing a desirable magneto-optical performance by utilizing an MPC heterostructure. The performance to be realized consists of a desirable transmittance along with a desirable Faraday rotation angle. The synthesis procedure gives the

There has been no study for measuring the comprehensive flow field of magnetic fluids. A pumpless transport system has been envisaged based on the temperature dependence of the magnetization of magnetic fluid; however, the knowledge regarding the internal flow is still limited. It is difficult to optimize the design and realize the practical use of the transport system using magnetic fluid. Therefore

In the heat-assisted magnetic recording (HAMR) process, the transition jitter is known to depend on the grain size as well as the heat spot thermal gradient. We find that the jitter also depends on the Voronoi grain size distribution, as well as exhibiting a surprising nonlinear dependence on reader width. By combining the noise due to these dependencies we used an analytical formulation to estimate

This letter presents a novel speed sensor based on motion-induced eddy currents in conductive moving parts. The magnetic yoke is an E-shaped ferrite core. The excitation coil is on the center leg of the E-core, and two antiserially connected pick-up coils are on the side legs. Solid iron and aluminum materials are used for the moving part in the simulations and in the measurements. Two-dimensional

In a bit-patterned media recording (BPMR) system, reducing the spacing between adjacent bit islands in the down- and cross-track directions increases areal density; however, two-dimensional (2-D) interference comprising intersymbol and intertrack interferences degrades the system performance. To mitigate error patterns that increase the 2-D interference in BPMRs, 2-D modulation coding schemes have

We report on magnetic properties of Fe–Ni–Ti alloys after severe plastic deformation (SPD) by high-pressure torsion (HPT) and low-temperature annealing. SPD and low-temperature annealing considerably change the magnetization behavior. The main magnetic and structural characteristics of bulk and HPT materials were determined. The addition of small amounts of Ti and annealing at 300 °C will not lead

Bit-patterned media recording (BPMR) is a candidate technology that extends the density to up to 4 Tb/in 2 to handle large amounts of data. However, in BPMR systems, the major challenge is two-dimensional (2-D) interference, which includes intersymbol interference from the down-track direction and intertrack interference from the across-track direction. To combat 2-D interference, it is natural to

This letter reports the development of low-damping yttrium-iron-garnet (YIG) thin films via sputtering. The films were deposited by sputtering at room temperature first and were then annealed in O 2 at high temperature. It is found that the annealing temperature critically affects the structural properties of the YIG films and thereby dictates the static and dynamic properties of the films. A 75 nm

Integration of yttrium iron garnet (YIG) with Si can bring new avenues for garnet-based complementary metal-oxide semiconductor compatible devices. Herein, investigations on the morphological, electrical, and magnetic properties of postgrowth annealed YIG thin films grown on Si substrate were systematically performed at nanoscale lateral resolution, employing the variants of atomic force microscopy

Spectral, temperature, and magnetic field dependences of the magneto-optical transversal Kerr effect (TKE) as well as optical properties of (In,Mn)As samples prepared by ion implantation followed by pulsed laser melting were studied, and a strong TKE response was detected at low temperatures. The presence of a characteristic structure in the TKE spectra in the transition region around the Λ point of

We present the fabrication process and characterization of a tunnel magnetoresistance sensor-based monolithic device assembled in Wheatstone bridge architecture, capable of measuring magnetic fields in both planar-sensitive directions simultaneously. This process is simplified in comparison with other fabrication strategies, as it does not require annealing or the usage of auxiliary structures to achieve

In this letter, we examine underwater wireless communications using electromagnetic waves in marine shallow waters. Due to the particular environment under study (low frequencies, short distances, and small loop antennas), a magnetoquasi-static approach is used instead of full-wave analysis. The electric field generated by a constant current circular loop placed on the interface between two conductors

We present a spring-shaped tunable inductor, fabricated using a silicon-on-insulator (SOI) multiuser micro-electromechanical system process. The inductor has a simple planar design and is monolithically integrated in the SOI wafer. The inductor is tuned using a thermal actuator on the same silicon structure layer. Thus, the complexity and cost of fabrication are greatly minimized. The device is compact

Magnetic insulators, in particular, rare-earth iron garnets, have low damping compared to metallic ferromagnetic materials due to lack of conduction electrons. In analogy to spin-transfer-torque devices, the low-damping nature is presumed to be an advantage for spintronic applications. We report that perpendicular magnetic anisotropy material with low damping actually does not favor reliable spin–orbit

Undoped ZnO nanostructures were deposited on Si (100) substrate using direct-current-unbalanced magnetron sputtering. The nanostructure modification of conelike into rod-shaped nanocolumnars is found after thermal annealing with O 2 . This modification transforms paramagnetism into room-temperature ferromagnetism, induced by Zn vacancy enhancement at the cost of O vacancies. First principles confirm

Recently, nonmetallic ferromagnetic nanowires (NWs) have been implemented in porous templates. Such composite substrates are used to design various microwave, magnetic, and electronic devices. To synthesize ferrite NWs, the precursor solution consists of either magnetic nanoparticles (NPs) dispersed in a polymer as a surfactant or metal nitrates, which are used in a sol–gel method. The magnetic properties

The use of amorphous ferromagnetic microwires has potential for applications in biomedicine and biophysics. Microwire arrays create magnetic fields that are characterized by strong spatial gradients. A system of ferromagnetic microwires with magnetizations across the diameter may efficiently accumulate paramagnetic particles along the wire due to forced diffusion. For typical system parameters, the

Micromagnets in the form of microwires have become a subject of interest in various applications including magnetic field bias elements in miniature actuators, sensors, and manipulators. While the preparation of hard magnetic microwires with sufficiently high magnetization is a difficult task, it can be achieved by using specific crystallization techniques. We present a technique for the fabrication

A miniature magnetic gradient tensor system may be used in small spacecraft for mineral prospecting and detection of unexploded explosive ordnance. The system consists of a magneto-inductive (MI) sensors array, a signal extraction circuit, and a microcontroller. A magnetic gradient full-tensor configuration utilizes four MI sensors arranged in a planar cross structure and is employed to minimize orientation

Flake-shaped FeSi-based metallic amorphous alloy particles, having an aspect ratio as high as 175:1, were prepared by ball-milling gas-atomized amorphous powders of an effective diameter of 20 µm. The starting powder has a saturation magnetic flux density Bs of 1.5 T and a coercivity Hc of 94 A/m. The aspect ratio of the flakes, as well as their magnetic properties, were controlled by milling process

We report the results of scanning tunneling microscopy experiments using iron-coated tungsten tips and current-carrying bismuth selenide (Bi $_2$ Se $_3$ ) samples. Asymmetry in tunneling currents with respect to the change in the direction of bias currents through Bi $_2$ Se $_3$ samples has been measured. It is argued that this asymmetry is the manifestation of surface spin-polarized electron accumulation

The magnetic domain structure of Y 2 (Fe $_{x}$ Co 1– $_{x}$ ) 17 (0.03 < $ x $ < 0.88) intermetallic compounds was investigated via magnetic force microscopy. It is experimentally shown that in the range of $x$ = 0.07 − 0.5, the surface magnetic domain structure of the single crystals reveals domains with typical uniaxial magnetocrystalline anisotropy configuration. The values of the surface energy

Magnetic particle imaging (MPI) is a fast and sensitive technique for imaging of magnetic nanoparticle (MNP) concentrations. MPI directly measures and maps the particle concentration over a measured spatial position. Functional MPI (fMPI) is a specific application of MPI that aims to detect the change of cerebral blood volume (CBV) through imaging. Assuming that the concentration of MNPs in the CBV

We provide a review of the status and challenges for utilizing magnetic tunneling junction (MTJ) based magnetic sensors for power grid applications. We show that, with both modeling and experimental measurement, an optimized MTJ-based magnetic sensor can be utilized to monitor grid current, especially for individual grid lines. From the perspective of the sensor, the sensitivity, signal-to-noise ratio

A set of planar Hall resistance (PHR) sensors was fabricated on rigid and flexible substrates. High signal-to-noise ratio, low offset voltage, nearly zero hysteresis of signal, and excellent linearity were demonstrated for sensors, based on Ta (5 nm)/NiFe (10 nm)/IrMn (10 nm)/Ta (5 nm) thin films, grown on polydimethylsiloxane (PDMS) and parylene C polymeric substrates. The effect of bending on the

Hexagonal platelet barium ferrite was produced through a two-step molten salt synthesis calcined at 850 °C for 5 h with NaCl–KCl as flux, followed by calcination at 400 °C for 5 h with hexamine. Influence of NaCl–KCl and hexamine on the structural, phase composition, surface morphology, and magnetic properties of BaFe 12 O 19 was studied by X-ray diffraction, Fourier transform infrared spectroscopy

The spacecraft-level magnetic budget in the framework of dc magnetic cleanliness programs of space missions is studied and analyzed. This analysis follows the unit-level magnetic characterization test campaigns that are performed in space missions with challenging magnetic cleanliness requirements. Taking into consideration the output of these test results,the total magnetic signature of the spacecraft

In this letter, a novel approach is presented for imaging of metallic objects based on induction sensing. The approach relies on the concept of collection of the point-spread function (PSF) in a linear space-invariant system. For this purpose, the responses of small objects are measured a priori to serve as the PSFs of the imaging system. Then, these PSFs are employed in a test scenario in which the

We present on-chip implementation of an isothermal nucleic acid amplification assay with optomagnetic detection. Isothermal rolling circle amplification (RCA) was designed for the highly specific detection of a single point mutation in the subsequence of the katG catalase peroxidase gene responsible for resistance against the antibiotic isoniazid in Mycobacterium tuberculosis . The assay was integrated

While the effect of bias direct currents on longitudinal giant magnetoimpedance (GMI) has been well studied, there have been very few investigations of their effect on perpendicular GMI. We report an experimental investigation of the influence of bias direct currents on perpendicular GMI in meander-line NiFe/Cu/NiFe/Cu/Cr films. The low-field sensitivity and linearity of perpendicular GMI both increased

We present results of magneto-optical investigations of (CoFeB) x -(Al-O) 100- x film nanocomposites in transverse Kerr effect (TKE) geometry in the spectral range 0.5–4.0 eV and magnetic field up to 3.1 kOe. Nanocomposites were deposited onto a glass-ceramic substrate by ion-beam sputtering. According to the data obtained from resistivity measurements, the percolation threshold is about x per ≈ 57 at

The centimeter-gram-second system of electromagnetic units (EMU) has been used in magnetism since the latter part of the 19th century. The International System of Units (SI), a successor to Giorgi's 1901 rationalized four-dimensional meter-kilogram-second system, was adopted by the General Conference on Weights and Measures in 1960 with the ampere as the fourth base unit. However, EMU remains in common

The International System of Units (SI) is expected to be revised such that all seven base units, including the kilogram, will be defined in terms of fixed numerical values of seven defining constants. The revised SI will include a redefinition of the ampere. One consequence is that the permeability of vacuum will not have a fixed numerical value but will become, in principle, a measurable quantity