Hiroto Masuda 교수

Abstract Non-magnetic materials exhibiting large spin-Hall effect (SHE) are eagerly desired for high-performance spintronic devices. Here, we report that non-equilibrium Cu-Ir binary alloys with compositions beyond the solubility limit are candidates as spin-Hall materials, even though Cu and Ir do not exhibit remarkable SHE themselves. Thanks to non-equilibrium thin film fabrication, the Cu-Ir binary alloys are obtained over a wide composition range even though they are thermodynamically unstab

Controllable antiferromagnetic alignment of magnetizations is vital for the systematic study of antiferromagnetic spintronics. Along this path, antiferromagnetically coupled metallic superlattices are promising systems, exploiting the interlayer exchange coupling. Here, the authors report that, as a spacer-layer material sandwiched between ferromagnetic cobalt layers, nonmagnetic Ir-doped Cu exhibits simultaneously a definite interlayer exchange coupling and an appreciable spin-orbit torque. Thi

The recently discovered antisymmetric interlayer exchange coupling (AIEC) plays pivotal roles in the magnetization switching of a synthetic antiferromagnet by inducing magnetization canting. Large AIEC is reported for perpendicularly magnetized $\mathrm{Pt}/\mathrm{Co}/\mathrm{Ir}/\mathrm{Co}/\mathrm{Pt}$ with wedge-shaped layers. The effective field of AIEC is related with symmetric interlayer exchange coupling, providing a guide for enhancing AIEC. We develop an extended Stoner--Wohlfarth mode

We report current-induced magnetization switching in Pt/Co/Ir/Co/Pt multilayers with different Ir layer thicknesses (tIr), where the perpendicularly magnetized Co layers are coupled ferromagnetically or antiferromagnetically through an interlayer exchange coupling and are sandwiched by the Pt spin Hall layers. The domain structures formed during switching vary depending on the magnetization alignment, i.e., a ferromagnetically coupled or antiferromagnetically coupled configuration. These results

Non-equilibrium Cu–Ir binary alloys are interesting materials because these alloys show a large spin Hall effect (SHE) despite the non-remarkable spin Hall angles of pure Cu and pure Ir. In this study, the temperature dependence of the SHE on a non-equilibrium Cu–Ir binary alloy was investigated in order to understand the mechanism of its large SHE. We measured the spin Hall magnetoresistance for the Cu76Ir24/CoFeB bilayer at various measurement temperatures. The spin Hall conductivity remains p

Current-induced domain-wall motion (CIDWM) in a synthetic antiferromagnet is a key phenomenon for developing potential high-density-packed magnetic domain-wall memory with fast operation. Here, CIDWM is reported in the antiferromagnetically-coupled two Co layers through the Ir interlayer sandwiched by the two Pt layers: Pt/Co/Ir/Co/Pt. The top and bottom Pt layers play a role for generating the spin current coming from the spin Hall effect, which gives rise to the dual spin-orbit torque (SOT) ac

Antiseismic devices, which control the damage of an apparatus and the device from earthquake vibration, play an important role for maintenance and continuation of social activities. Though three-dimensional antiseismic devices have a function to reduce the vibration component of each the horizontal and vertical directions, in the vertical direction, the correspondence structure is complicated from the need to find rigidity to support target mass in particular. Therefore, for reasons of vertical

Hinged-leg type continuous unloaders in which each leg on the sea side is fixed by a pin to the main body are often used for bulk handling in sea ports. For such type of unloaders, we proposed an antiseismic device using linear ball bearing and laminated rubber bearing installed between the traveling gears and the fixed-legs on the land side. Vibration experiments using 1/15 scale model of an actual unloader, and transient response analysis were conducted to evaluate the analysis method and the

As material-handling equipment for unloading bulk materials such as iron ore and grain from vessels at harbor piers, continuous unloaders play an important role from the viewpoint of handling performance and environmental protection. Among the various types, belt conveyor-type unloaders are required to provide highly versatile handling performance covering low- to high-fluidity bulk materials. When low-fluidity bulk materials are handled, handling performance decreases and electric energy consum

Continuous unloaders play an important role in handling bulk materials at ports and so should be fitted with antiseismic devices to protect them in case of emergency by severe earthquakes. Continuous unloaders usually have a hinged-leg type structure and their posture changes over a wide range during operations. For the seismic design of continuous unloaders and to optimize antiseismic devices for them, these features must be taken into consideration and the dynamic behavior of unloaders under r

Continuous unloaders play an important role in handling bulk products at ports and so should be fitted with antiseismic devices to protect them in case of emergency by severe earthquakes. Continuous unloaders usually have a hinged-leg type structure and their posture changes over a wide range during operations. For the seismic design of continuous unloaders and to optimize antiseismic devices for them, these features must be taken into consideration and the dynamic behavior of unloaders under re