2016年 第77回応用物理学会秋季学術講演会

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[13p-P8-1~46] 10 スピントロニクス・マグネティクス(ポスター)

2016年9月13日(火) 16:00 〜 18:00 P8 (展示ホール)

16:00 〜 18:00

[13p-P8-13] Spacer layer insertion effect on magnetic properties of Cr2O3/Co exchange coupling system

Tomohiro Nozaki1、Satya Prakash Pati1、Tatsuo Shibata2、Shougo Yonemura2、Tetsuya Nakamura3、Yoshinori Kotani3、Muftah K O Al-Mahdawi1、Shujun Ye1、Yohei Shiokawa1、Masashi Sahashi1,4 (1.Tohoku Univ.、2.TDK corporation、3.JASRI、4.ImPACT program)

キーワード:perpendicular exchange bias, spacer layer, magnetoelectric effect

Magnetoelectric material Cr2O3 has received much attentions as a promising candidate for voltage-controlled spin devices. We have demonstrated the voltage control of perpendicular exchange bias in Cr2O3/Co all thin film system [1,2], which make the practical applications more realistic. In these reports, it was essential to reduce the magnitude of exchange bias (Hex) by inserting metal spacer layer such as Pt and Cr between Cr2O3 and Co to achieve the voltage-control of perpendicular exchange bias. It is noted that the role of metal spacer layers are not only reduce the magnitude of Hex by make “space” between Cr2O3 and Co. The spacer layers largely affect to the magnetic properties of Co. In this study, we investigated the spacer layer effect on Hex and magnetic properties of Co.
We use three metals, Pt, Ru, and Cr, for spacer layer. The sample structure is Al2O3 sub./Pt 25/Cr2O3 250/spacer/Co 1/Pt 5(nm). Figure 1 shows the typical magnetization curve with different spacer layers. Obviously, the magnetic anisotropy differ according to the spacer materials. In additions, difference in magnetization was clearly observed. The spin polarization of Pt spacer or cap layer partly contribute to the results. We will discuss the difference based on the X-ray magnetic circular dichroism (XMCD) results of Co.
This work was partly funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Japan Government).
[1] T. Ashida et al., Appl. Phys. Lett., 104 (2014) 152409.
[2] T. Ashida et al., Appl. Phys. Lett., 106 (2015) 132407.