[16p-D704-1~18] 10.4 半導体・トポロジカル・超伝導・強相関スピントロニクス

▼ [16p-D704-8] Magnetic-field-controllable resistive-switching and spin-valve-like behavior in an Fe/MgO/Ge-based two-terminal device

〇Masaya Kaneda¹、Shun Tsuruoka¹、Hiroshi Yoshida²、Tatsuro Endo¹、Yuriko Tadano¹、Masaaki Tanaka^1,2、Shinobu Ohya^1,2 (1.Department of Electrical Engineering and Information Systems, The University of Tokyo、2.Center for Spintronics Research Network (CSRN), The University of Tokyo)

キーワード：resistive-switching, germanium, spintronics

Resistive switching (RS) has been intensively investigated, evoking interest due to their potential applications to next-generation nonvolatile memory and neuromorphic computing. The next essential requirement for further development of the RS devices is multi-functionalization. From this point of view, the magnetic-field dependence of RS has been studied for the metal/insulating oxide/metal devices; however, the current status is far below the level of the full use of the potential of the multi functions of RS. Previously, our group observed the RS effect in two-terminal devices composed of Fe/MgO/Ge heterostructures. Here, we present, for the first time, an unusual magnetic-field-controllable RS of the Fe/MgO/Ge heterostructure, whose MR-curve shape is similar to that of the spin-valve effect, with a large magnetoresistance (MR) ratio of up to 18900%, when applying appropriate bias voltages. In our device, the I–V curve has a hysteresis loop with an unusually large dependence on the magnetic field H applied along the [010] direction in the film plane; the threshold voltage, at which the current abruptly increases, increases with increasing |H|. Using this hysteretic behavior of the I–V characteristics depending on H, we obtain spin-valve-like MR curves with a clear minor loop. Our results suggest that this device has the potential as a nonvolatile memory with high magnetic-field sensitivity under specific bias conditions.