2019年第66回応用物理学会春季学術講演会

講演情報

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

[11p-M101-15~21] 10.3 スピンデバイス・磁気メモリ・ストレージ技術

2019年3月11日(月) 17:15 〜 19:00 M101 (H101)

近藤 浩太(理研)

18:00 〜 18:15

[11p-M101-18] Giant MR Ratio by Using Metastable bcc-Cu Spacer Layer in Epitaxial Current In-Plane Giant Magnetoresistance Devices

〇(M2)Kresna Bondan Fathoni1,2、Yuya Sakuraba1、Taisuke Sasaki1、Yoshio Miura1、Jinwon Jung1、Tomoya Nakatani1、Kazuhiro Hono1 (1.NIMS、2.Univ. of Tsukuba)

キーワード:giant magnetoresistance, sensor, bcc Cu

In current in-plane giant magnetoresistance (CIP-GMR), large value of magnetoresistance (MR) ratio is necessary for various sensor applications. It is well known that good lattice and band matching is necessary to obtain large MR ratio. We investigated epitaxial bcc Co1-xFex-based CIP-GMR spin valves with thin Cu spacer. The stacking of MgO subs./Co1-xFex/Cu/Co1-xFex/IrMn/Ta were deposited by sputtering with x = 10, 25, 50, 67 and 100. The largest observed MR ratio of 26% in Co50Fe50. Then we use Co50Fe50 for new design of MgO subs./Co50Fe50/Cu/Co50Fe50/MgO to introduce a specular reflection from MgO to enhance MR ratio. As a result, we observed giant MR of 40% which is the highest MR in trilayer CIP-GMR ever reported. Our TEM analysis confirmed Co50Fe50 and Cu layers coherently connected without any dislocation due to the formation of bcc Cu spacer. Our first principle calculation confirmed that the good band matching of bcc Cu and Co50Fe50 is the origin for observed giant MR ratio.