Ultrafast control of the magnetization in ps timescales by fs laser pulses offers an attractive avenue for applications such as fast magnetic devices logic and memory. However, ultrafast helicity-independent all-optical switching (HI-AOS) has thus far only been observed Gd-based, ferrimagnetic amorphous (\textit{a}-) rare earth-transition metal (\textit{a}-RE-TM) systems, a comprehensive understanding reversal mechanism remains elusive. Here, we report HI-AOS...

Ultrafast magnetization switching at picosecond and sub-picosecond time scales has tremendous technological potential but still poses numerous questions regarding the underlying quantum mechanical phenomena, including roles of interactions between electrons, spins, phonons (lattice). At nanometer-scale dimensions relevant for modern applications, these phenomena become increasingly more pronounced. Until now, helicity-independent all-optical (HI-AOS) been largely limited to amorphous...

Challenges posed by the chemical incompatibility between nanoparticles and polymer matrices hinder widespread use of nanocomposites as material platform for many innovations. In this study, we demonstrate effectiveness a versatile approach to surface functionalization commercial nanoparticles. To illustrate importance proper functionalization, process was used functionalize high-moment iron enhance magneto-mechanical performance nanoparticle-based magnetorheological elastomers (MREs). We...

Composite multiferroic systems, consisting of a piezoelectric substrate coupled with ferromagnetic thin film, are great interest from technological point view because they offer path toward the development ultralow power magnetoelectric devices. The key aspect those systems is possibility to control magnetization via an electric field, relying on magneto-elastic coupling at interface between and components. Accordingly, direct measurement both electrically induced magnetic behavior...

Haptics allows tactile interactions between humans and digital interfaces. Magnetorheological elastomers (MREs) constitute a promising candidate material for creating the interface of future─one able to recreate 3D shapes that can be sensed with touch. Furthermore, an MRE formed by using nanoparticles, as opposed previously used microparticles, is necessary generate variety involving sharp curvatures over small, micrometer-scale horizontal distances pave way haptic displays microtexture...

Magnetic nanoparticle chains offer the anisotropic magnetic properties that are often desirable for micro- and nanoscale systems; however, to date, large-scale fabrication of these nanochains is limited by need an external field during synthesis. In this work, unique self-assembly nanoparticles into as a result their intrinsic dipolar interactions only examined. particular, it shown in high concentration reaction regime, dipole-dipole coupling between two neighboring iron cobalt (FeCo)...

Integrated interleaved solenoid transformers with a single layer of laminated magnetic core have been designed and fabricated. A coupling coefficient > 0.97 was achieved for device primary secondary inductance 565 nH, which represents an enhancement more than 60 times that air inductors identical geometry. By using the structure, quality factor or increased to peak value 6.3 3 μm thick electroplated copper coils. Measured characteristics integrated agree very well simulation results values...

Abstract The precise control of magnetic properties at the microscale has transformative potential in healthcare and human‐robot interaction. This research focuses on understanding interactions nanostructure assemblies responsible for microactuation. By combining experimental measurements micromagnetic simulations, both nanocube nanochain are elucidated. Hysteresis first‐order reversal curves (FORC) reveal that spatial arrangement these governs their collective magnetism. A critical...

A major obstacle to building nanoscale magnetic devices or even experimentally studying novel nanomagnetic spin textures is the present lack of a simple and robust method fabricate various nano-structured alloys. Here, theoretical experimental investigations were conducted understand underlying physical mechanisms particle self-assembly in zero applied field. By changing amount NaOH added during synthesis, we demonstrate that resulting morphology assembled FeCo structure can be tuned from...

The demand on mobile electronics to continue shrink in size while increasing efficiency drives the internal passive components do same. Power amplifiers require inductors with small form factors, high quality factors (Qs), and operating frequency single-digit gigahertz range. This paper explores use of magnetic materials satisfy demands power amplifier inductor applications. then discusses optimization choices regarding material selection, device design, fabrication methodology. achieved...

Magnetoelectrics have attracted much attention for their ability to control magnetic behavior electrically and electrical magnetically. This feature provides numerous benefits electronic systems can potentially serve as the bridge needed integrate devices into mainstream electronics. Here, this natural next step is pursued thin‐film integrated magnetoelectric are produced radio‐frequency (RF) The first fully integrated, modulators tunable RF electronics presented. These provide electric...

Control of spin-orbit torques (SOTs) in heavy metal/ferromagnetic metal/oxide structures is critical to the realization promising SOT magnetic random access memory devices. In this paper, SOT-induced effective fields Ta/CoFeB/Mg(MgO) with perpendicular anisotropy (PMA) were investigated through low-current-induced lock-in technique. This paper demonstrates that industrially preferred MgO preparation method allows us readily manipulate oxidation degree Mg(MgO) and produce a significant effect...

Varying strengths of perpendicular magnetic anisotropy, required for spintronics and high-frequency applications, are engineered in amorphous GdCo through stoichiometric changes, oxygenation multi-repetition heterostructures.

The development of reliable and highly energy efficient multiferroic nanosystems, which can function at room temperature, is key for the design ultralow-power magnetoelectric devices. Here, we report electrically controlled magnetic domain wall motion magnetization switching in $\mathrm{BaTi}{\mathrm{O}}_{3}\text{/}\mathrm{C}{\mathrm{o}}_{50}\mathrm{F}{\mathrm{e}}_{50}$ microstructures, temperature. perfect one-to-one connection between ferroelectric pattern $\mathrm{BaTi}{\mathrm{O}}_{3}$...

In-plane magnetized films of CoTaZr demonstrate standing spin-wave resonances in the complex permeability spectra well below ferromagnetic resonance frequency. From detailed analysis static field dependence modes combined with observation domains using Kerr microscopy, we show that these originate from spin waves within Bloch walls where magnetization rotates perpendicular to plane film. Unlike typically described perpendicularly films, frequencies involved are much lower due unique dynamics...

The magnetic permeability frequency spectrum is one of the most critical properties for operation high devices in gigahertz regime. Permeability fairly constant up to ferromagnetic resonance (FMR) frequency, at which point relative drops unity. Extending FMR higher frequencies thus imperative developing GHz-range devices. simulation and experimental investigations presented this paper demonstrate how stacking layers form a laminated film increases by allowing flux closure between along...

Magnetic cores produced by laminating alternating magnetic/nonmagnetic layers have been shown to eliminate closure domains linking flux vertically between magnetic at the edge of film. Closure domains, which do not contribute significantly permeability, are undesired in patterned for transformers since they reduce inductance. The inductance narrow core was found drop with increasing frequency. Kerr images these reveal partial edges, explain behavior. Edge domain effects explained based upon...

Partially perpendicular anisotropy in Permalloy thin films was found to produce reliably isotropic permeability the plane of film. Isotropic is especially desirable for integrated closed-loop magnetic solenoid inductors order create an efficient return path flux. Material properties were verified through hysteresis loop, permeability, and magneto-optic Kerr effect microscopy utilized simulate behavior inductor. Laminated with partially yielded a relatively high value 860 isotropically...

Magnetic materials have been utilized to increase the inductance of integrated inductors by taking advantage their high-permeability [1]-[3]. It has shown simulation magnetic flux in a closed-core inductor that films with isotropic permeability are promising. Utilizing core uniaxial hard axis inevitably produces an effective air-gap, which inefficiently closes loop [4]. In order obtain both longitudinal and transverse directions film, CoZrTa film was deposited induced easy at 45° angle from...

High-frequency permeability spectra and magnetic domain structures of CoZrTa films with 45° induced anisotropy were investigated in order to realize integrated flux-closed inductors. Isotropic was experimentally achieved for both in-plane parallel transversal directions. The obtained relative ~380 the directions unpatterned sample is approximately half conventional hard-axis as expected from a magnetization rotation model. Once are micropatterned, typically degraded by formation spike...

We investigate the influence of dislocations and twin walls in ${\mathrm{BaTiO}}_{3}$ on its ferroelectric response resulting effect perpendicular magnetic anisotropy (PMA) a strain-coupled ${[\mathrm{Co}\ensuremath{\setminus}\mathrm{Ni}]}_{\mathrm{n}}$ film. A dense twinned structure conjunction with high dislocation density significantly reduces converse piezoelectric by hindering propagation newly nucleated domains an applied electric field. This, turn, results modest reduction PMA...