[16p-Z19-1~23] 10.1 新物質・新機能創成（作製・評価技術）

▼ [16p-Z19-9] Oxidation State in Perpendicularly Magnetized Fe/CrO/MgO studied by X-ray Absorption Spectroscopy

〇(D)Yuki Iida^1,2、Qinqyi Xiang²、Thomas Scheike²、Zhenchao Wen²、Jun Okabayashi³、Tadakatsu Ohkubo²、Kazuhiro Hono^1,2、Hiroaki Sukegawa²、Seiji Mitani^1,2 (1.Univ. of Tsukuba、2.NIMS、3.The Univ. of Tokyo)

キーワード：perpendicular magnetic anisotropy, Fe/CrO, layer-exchange growth

Single-crystalline Fe/MgO(001) interface shows large interfacial perpendicular magnetic anisotropy energy K_i of 2.0 mJ/m² when they were grown using molecular beam epitaxy (MBE) or electron beam evaporation (EB).In this study, the magnetic propeties and structures of sputter-deposited single-crystalline Cr(30 nm)/Fe(0.7 nm)/MgO(2 nm) were investigated. In the stacks without post annealing, the oxidation of Fe layer was confirmed. After annealing, a rock salt type CrO layer was formed between the Fe and MgO layers. K_i of 1.55 mJ/m² was achieved in Fe/CrO/MgO. X-ray absorption spectroscopy measurements revealed the redox reaction of Fe-oxide by Cr, and the valence state of Cr was deduced to be less than 2+.