講演情報
[16p-S2_201-5]Room-temperature spin-valve effect via surface conduction in SrTiO3
〇Minori Osaki1, Tatsuro Endo1, Keita Hidaka2, Aoi Nakamura1, Shinobu Ohya1,3, Masaaki Tanaka1,3 (1.UTokyo, EEIS, 2.UTokyo, EEIC, 3.CSRN)
キーワード：
spintronics、spin-valve effect、Room temperature operation
We demonstrate, for the first time, a room-temperature spin-valve effect utilizing surface conduction in SrTiO3 (STO). In this study, we fabricated an all-epitaxial Fe/STO structure with a 100-nm channel defined by Ar irradiation. Clear spin-valve signals with a magnetoresistance (MR) ratio of 0.14% were observed at 300 K, consistent with theoretical predictions based on a diffusive-transport model. Notably, at 50 K, sharp peaks characteristic of the spin-valve effect were observed, reaching an MR ratio of 1.0%. The spin signals exhibited no angular dependence and remained consistently positive, distinct from the behavior observed in a reference device without a trench. This result excludes the possibilities of anisotropic magnetoresistance (AMR) and tunneling anisotropic magnetoresistance (TAMR), confirming that the signals originate from a genuine spin-valve effect. These findings provide important guidelines for achieving room-temperature operation and for device applications in oxide spintronics.