Pt/Co/TiO2 수직자기이방성 박막의 저전류 고속 자구벽 운동 관측

Abstract

Controlling domain-walls (DWs) by low electric current with high speed is the key for excellent performance of spintronic memory and logic devices. Accordingly, many researchers have devoted their efforts to faster DW speed In this paper, we report that, with appropriate choice of oxidation condition, the DW moves ~100m/s with current density ~low 〖10〗^11A/m^2 on Pt/Co/TiO_2 perpendicularly magnetized anisotropic (PMA) micro-wire structure. Additionally, through this work, Pt/Co/TiO_2 PMA structure and its properties were introduced for the first time. For this study, firstly, we fabricated naturally oxidized Pt/Co/TiO_x flims and confirmed x=2 through XPS data. The detailed film structure is 5-nm Ta/3-nm Pt/0.45-nm, 0.5-nm Co/1.5-nm TiO_x, which is deposited on Si/SiO_2wafers by use of dc magnetron sputtering. Secondly, we deposited Pt/Co/TiO_2 films with various oxidation condition. Finally, after patterning micro-wire, we observed DW moves ~100m/s with current density ~low 〖10〗^11A/m^2 To investigate current induced domain wall motion, we used MOKE microscope with 780 nm wavelength laser The present observation provides a good starting point to achieve higher performance of DW-mediated spintronic devices with a faster DW speed.