We report direct full-field magneto-optical observations of Barkhausen avalanches in Co polycrystalline thin films at criticality. provide experimental evidence for the validity a phenomenological model avalanche originally proposed by Cizeau, Zapperi, Durin, and Stanley [Phys. Rev. Lett. 79, 4669 (1997)]], where describes 180 degrees -type flexible domain wall deformed localized defect with consideration long-range dipolar interaction. The jump areas show power-law scaling distribution...

We first report the all-electrical spin injection and detection in CoFe/MgO/moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable signal of ~170 k{\Omega} {\mu}m^2 has been observed RT, analysis using a single-step tunneling model gives lifetime ~120 ps diffusion length ~683 nm Ge. The shows asymmetric bias dependences which are strongly related to asymmetry process.

We investigate the intrinsic Gilbert damping constant in perpendicular magnetic anisotropy Co/Ni multilayer system by means of an all-optical method. find that does not depend on stack number and when field is high enough. In contrast, extrinsic strongly correlated with inhomogeneous distribution low-field regime, as observed magneto-optical images. Intriguingly, consistently reduced decreasing length scale measurements, providing a concrete to determine damping.

Abstract The utilization of ferromagnetic (FM) materials in thermoelectric devices allows one to have a simpler structure and/or independent control electric and thermal conductivities, which may further remove obstacles for this technology be realized. thermoelectricity FM/non-magnet (NM) heterostructures using an optical heating source is studied as function NM number multilayers. It observed that the overall signal those structures contributed by spin Seebeck effect anomalous Nernst (ANE)...

An interacting quantum dot side-coupled to a perfect wire is studied. Transport through the investigated by using an exact sum rule and slave-boson mean field treatment. It shown that Kondo effect provides suppression of transmission due destructive interference ballistic channel channel. At finite temperatures, anti-resonance behavior found as function level position, which interpreted crossover from high temperature phase low charge fluctuation phase.

We report the electrical spin accumulation with enhanced bias voltage dependence in n-type Si, employing a crystalline CoFe/MgO tunnel contact. A sizable signal of ∼4.8 kΩμm2, lifetime ∼155 ps, and diffusion length ∼220 nm were obtained at 300 K. The this system show consistent behavior temperature variation irrespective voltage. Notably, exhibits nearly symmetric respect to polarity, which is ascribed improved polarization.

The relationship between Gilbert damping and magneto-crystalline anisotropy is studied here using an all-optical method in a perpendicular Co/Ni multilayer system by varying the Ti-buffer thickness. As thickness increases, enhanced. time-resolved Kerr signal of each sample well described its own intrinsic constant wide range external magnetic field. Interestingly, we find that constants increase linearly from 0.021 to 0.036 when samples varies 2.4 3.4 Merg/cm3. Such linear implies spin-orbit...

We have developed simplified analytic expressions for magneto-optical Kerr effects of both optically thick and ultrathin films in the general case, where a magnetic medium had an arbitrary direction magnetization beam light was obliquely incident to medium. It found that formulae p s waves consisted product two factors films: prefactor dependent only on optical parameters system main factor polar effect normal incidence case. also derived some useful relations among longitudinal...

Spin-reorientation transition (SRT) behaviors in ultrathin Co films grown on both Pt(111) and Pd(111) single-crystal substrates are investigated with situ magneto-optical Kerr effects. At the region of SRT from perpendicular to in-plane magnetization increasing thickness, canted out-of-plane orientations observed, which we can determine not only effective second- ${(K}_{2})$ but also fourth- ${(K}_{4})$ order anisotropy constants. Both constants, be separated into bulk ${K}_{2b(4b)}$...

Abstract We have synthesized maghemite (γ‐Fe 2 O 3 ) nanoparticles using chemical coprecipitation technique through a typical pipette drop method (pipette diameter: 2000 μm) and piezoelectric nozzle (nozzle size: 50 μm). The size distribution of the prepared by is from 5 nm to 8 nm. However, made show smaller very narrow Zero‐Field‐Cooled (ZFC)/Field‐Cooled (FC) magnetization magnetic hysteresis measurement were performed superconducting quantum interference device (SQUID) magnetometer K 300...

The spin engineering of CoxPd1−x alloy films on Pb(Zr0.52Ti0.48)O3 substrates was studied by measuring the polar Kerr rotation hysteresis loops and their electric field dependencies. dependence strongly depends composition CoPd alloys. This is especially so in case Co0.25Pd0.75 film where loop magnetic remanence with respect to voltage applied nearly squared, i.e., direction magnetization maintains its initial state even when turned off. a ferromagnetic/piezoelectric hybrid system possible...

We report the experimental results on magnetization reversal in Co/Pd multilayers. Interestingly enough, phenomena this system were found to be strongly dependent magnetic properties varied with Co-sublayer thickness. Direct domain observations and viscosity measurements revealed that wall motion was dominant samples having 2-\AA{}-thick Co sublayer, whereas nucleation those 4-\AA{}-thick sublayer. Magnetization theoretically studied using a nanomagnetic model strong dependence of behavior...

We have investigated the ultrafast magnetization dynamics of L10-ordered Fe50Pt50 thin film by means a time-resolved magneto-optical Kerr effect measurement. found high Gilbert damping value α∼0.26, together with very precession frequency f∼85 GHz and shortest relaxation characteristic time τ∼6.5 ps ever reported. believe that FePt unique property will be useful for realization picosecond spin switching.

This paper shows the study of preswirl duct as an effective energy saving devices that have been devised and reviewed to support propeller performance, especially for ship VLCC with large block coefficients. From bare hull wake measurements, typical upper/lower asymmetry at disk was found. The 2 kinds pre-swirl duct, Unconventional half circular Conventional designed recover loss running in condition. general function set work against this generate pre-swirled flow into ro-tating direction....

The present study aims to determine the appropriate size of mesh or number element (NoE) for flat- and curved plates, which is suggested assess its safety subjected axial compression based on ultimate limit state (ULS) design analysis concept. unstiffened panel (= plate) stiffened panel, considered primary members ships ship-shaped offshore structures, are repeated tension caused by continued vertical bending moments applied hull girder. Plates attached with stiffeners welding, 6, 8 10...

An interacting quantum dot inserted in a mesoscopic ring is investigated. A variational ansatz employed to describe the ground state of system presence Aharonov-Bohm flux. It shown that, for an even number electrons with energy level spacing smaller than Kondo temperature, persistent current has value similar that perfect same radius. On other hand, odd electrons, found be strongly suppressed compared ideal ring, which implies suppression Kondo-resonant transmission. Various aspects...

A novel method for the fabrication of patterned arrays Co/Pt by using colloidal lithography with reactive ion etching is described. Specifically, we created magnetic metal patterns controllable features RIE-assisted masks, and analyzed properties dots.

An ultrafast spin demagnetization process of an amorphous Tb35Fe65 alloy film has been investigated by means all-optical pump-probe technique. Interestingly, steplike on a subpicosecond time scale is observed before much slower change tens picoseconds. The at the explained extended three-temperature model considering interaction between nonthermal electron and system. characteristic TbFe expected to be very useful in manipulation state regime.

A theoretical study on the reorientational transition from in-plane to out-of-plane magnetized state is performed for two-dimensional magnetic dot arrays coupled by magnetostatic interaction. The square lattice of nanoscale cylindrical dots considered with assumptions that are magnetically soft and they have uniform magnetization. present predicts interdot coupling determines reorientation close-packed such dots. Recent experimental results nanometer-scale single-domain discussed in light...

We report the difference in activation volumes of wall-motion and nucleation processes Co/Pd multilayers. Each volume was estimated from field dependence speed rate, obtained by real-time domain imaging using a magneto-optical Kerr effect microscope. Delicate analysis shows that two are generally unequal ratio between varies noticeably 0.9 to 1.1 with change multilayered structure. found inequality has crucial influence on magnetization reversal behavior: process having smaller dominates.