Materials Development Division

Magnetic Materials

Koki TAKANASHI PHOTO
Prof. Koki TAKANASHI
Assoc.Prof. Takeshi SEKI
Assist. Prof. Takahide KUBOTA
Assist. Prof. Keita ITO

Materials Fabrication for Spintronics by Artificial Nanostructure Control

Magnetic properties based on electron spins are closely correlated with electronic transport properties in magnetic nanostructures, which makes it possible to control electric signals by magnetic signals, and conversely, magnetic signals by electric signals. A new electronics utilizing this mutual control is called spintronics. Our group works on the fabrication of materials and the fundamental study of physical phenomena for spintronics. Particularly, we are interested in ordered alloys with a variety of functionalities, and fabricate nano-layered structures or composite device structures with magnetic ordered alloys to investigate novel magnetic and magneto-transport properties. Prominent results obtained to date include the observation of giant spin Hall effect and the demonstration of spin wave-assisted magnetization switching in device structures with high magnetic anisotropy L10-FePt, and the enhancement of giant magnetoresistance effect and the observation of highefficiency spin torque oscillation using half-metallic Heusler alloys.

spintronics, nanomagnetism, ordered alloys
Experimental and calculated results of spin wave-assisted magnetization switching in an FePt / Permalloy (Py) bilayer.

Experimental and calculated results of spin wave-assisted magnetization switching in an FePt / Permalloy (Py) bilayer. The excitation of spin wave remarkably reduced the switching field(Hsw) of the bilayer.

ハーフメタルホイスラー合金(Co2Fe0.4Mn0.6Si)を用いた高出力巨大磁気抵抗素子(a, b) デバイスの透過電子顕微鏡像。(c) 室温における磁気抵抗曲線。

The device for the giant magnetoresistance effect using a half-metallic Heusler alloy, Co2Fe0.4Mn0.6Si. (a, b) Transmission electron microscope images, and (c) magnetoresistance curves of the device.

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