2021年第82回応用物理学会秋季学術講演会

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一般セッション(口頭講演)

10 スピントロニクス・マグネティクス » 10.3 スピンデバイス・磁気メモリ・ストレージ技術

[11a-S302-1~11] 10.3 スピンデバイス・磁気メモリ・ストレージ技術

2021年9月11日(土) 09:00 〜 12:00 S302 (口頭)

重松 英(京大)、藤田 裕一(物材機構)

10:45 〜 11:00

[11a-S302-7] Spin-orbit torque magnetization switching in a perpendicularly magnetized full Heusler alloy Co2FeSi

〇(P)Miao JIANG1、Eisuke Matsushita2、Yota Takamura2、Shigeki Nakagawa2、Shinobu Ohya1,3,4、Masaaki Tanaka1,3 (1.EEIS, Univ. of Tokyo、2.EEE, Tokyo Tech、3.CSRN, Univ. of Tokyo、4.IEI, Univ. of Tokyo)

キーワード:spin-orbit torque switching, Heusler alloy, perpendicular magnetic anisotropy

As one of the next-generation memory technologies, magnetic random access memory (MRAM) is of great research interest because of its non-volatility, high access speed, large integration density and low power consumption. Current-induced spin-orbit torque (SOT) magnetization switching has been proposed for improving the writing performance of MRAM. Meanwhile, it has been demonstrated that the Co-based full Heusler alloys show potential for increasing the magnetoresistance ratio and achieving efficient reading due to their relatively large spin polarization. Therefore, achieving the SOT magnetization switching in full Huesler alloys will be promising for optimizing both the reading and writing performance of MRAM devices.
Here, we report a successful full SOT magnetization switching in a perpendicularly magnetized full Heusler alloy Co2FeSi by using Pd as a spin current generating layer. A pulse current with a pulse width of 0.1 ms is applied to induce the magnetization switching. With the assistance of the external magnetic field of 500 Oe, the magnetization can be fully switched with a switching current density of 3.7x107 A cm-2, which is in the same order of magnitude as that required in the conventional heavy metal (HM)/ferromagnet system even though the Pd shows a relatively smaller spin Hall angle than that of HM. The damping-like and field-like effective fields (HDL and HFL) are quantified to be 70 Oe and 49 Oe, respectively by using harmonic Hall measurements. Our findings will advance the development of MRAM with both better reading and writing performance.
This work was partly supported by Grants-in-Aid for Scientific Research (Nos. 18H03860, 20H05650, and 20F20366), CREST Program of JST (JPMJCR1777), Spintronics Research Network of Japan (Spin-RNJ), and Grant-in-Aid for JSPS Fellows (20F20366).