2017年第78回応用物理学会秋季学術講演会

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10 スピントロニクス・マグネティクス » 10.2 スピン基盤技術・萌芽的デバイス技術

[6a-C18-1~12] 10.2 スピン基盤技術・萌芽的デバイス技術

10.1と10.2と10.3のコードシェアセッションあり

2017年9月6日(水) 09:00 〜 12:00 C18 (C18)

齋藤 秀和(産総研)

10:30 〜 10:45

[6a-C18-7] Temperature dependence of the spin-charge conversion under the ferromagnetic resonance condition in the YIG/CoFeB system

Sergey Dushenko1、Gregory Kopnov2、Alexander Gerber2、Teruya Shinjo1、Yuichiro Ando1、Masashi Shiraishi1 (1.Kyoto Univ.、2.Tel Aviv Univ.)

キーワード:spin pumping, spin-charge conversion, ferromagnetic resonance

CoFeB is a ferromagnetic material that is mostly famous due to being used in magnetic tunnel junction-based devices [1]. Recently, CoFeB is also used as a spin source in the spin pumping experiments. However, in such experiments, spin-source layer itself generates additional voltage [2], which can drastically affect estimation of the spin Hall angle of the studied material [3]. We studied the temperature dependence of the voltage generated under the spin pumping condition into the CoFeB layer, and under the ferromagnetic resonance condition of the CoFeB itself, which can help correctly analyze data in spin pumping experiments using CoFeB.
CoFeB layers were grown on top of the gadolinium gallium garnet/yttrium iron garnet (YIG) substrate. Samples were mounted inside the TE011 cavity of the electron spin resonance system with the external magnetic field applied in plane of the samples. Under the YIG ferromagnetic resonance condition, the magnetization precession of the YIG layer drove pure spin current into the adjacent CoFeB layer. The spin current inside the CoFeB layer was converted into the charge current via the inverse spin Hall effect, and the generated voltage was measured at the ends of the sample in the temperature range 140 K – 297 K. As a second part of the experiment, we carried out same measurements, but under the CoFeB layer (instead of YIG) ferromagnetic resonance conditions. The temperature evolution of the magnetic properties and the generated voltage are discussed in detail [4].

[1]. S. Ikeda et al., Appl. Phys. Lett. 93, 082508 (2008).
[2]. A. Tsukahara et al., Phys. Rev. B 89, 235317 (2014).
[2]. D.-J. Kim et al., Curr. Appl. Phys. 14, 1344 (2014).
[4]. S. Dushenko et al., in preparation.