[20a-B101-1~10] 10.3 スピンデバイス・磁気メモリ・ストレージ技術

▼ [20a-B101-4] Film-type strain gauge using CoFeB/MgO-based magnetic tunnel junction

〇(M2)Kenta Saito¹、Akiko Imai¹、Shinya Ota^1,2、Akira Ando¹、Tomohiro Koyama^1,3,4、Daichi Chiba^1,3,4 (1.SANKEN, Osaka Univ.、2.The Univ. of Tokyo、3.CSRN, Osaka Univ.、4.OTRI, Osaka Univ.)

キーワード：spintronics, magnetic tunnel junction, strain gauge

Mechanical quantities are one of the most important sensing targets in the physical space, and strain gauges play a major role to detect them. A gauge factor G_F, which is a sensitivity of a strain gauge, is given by the ratio of relative change in resistance to the strain. A typical G_F of a conventional metal foil gauge is ~2. We have recently demonstrated strain sensing using a flexible giant magnetoresistive device, where the magnetization direction changes with the strain due to the magnetoelastic effect. In this device, one order higher G_F than that of the conventional one is achieved. G_F is expected to be further improved by utilizing the tunnel magnetoresistance effect. Thus, we examined a flexible CoFeB/MgO-based magnetic tunnel junction to realize much higher G_F.