[20a-B101-1~10] 10.3 Spin devices, magnetic memories and storages

▼ [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.)

Keywords: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.