Title :
Experimental Study of Thermally Activated Magnetization Reversal With a Spin-Transfer Torque in a Nanowire
Author :
Kim, Seon Ock ; Kim, Woo Jin ; Kim, Kab-Jin ; Choe, Sug-Bong ; Jang, Young Man ; Yoon, Seung Ha ; Cho, Beong Ki ; Lee, Taek Dong
Author_Institution :
Dept. of Mater. Sci. & Eng., KAIST, Daejeon
Abstract :
The current-induced domain-wall depinning in ferromagnetic nanowires with perpendicular magnetic anisotropy is investigated. The nanowire patterns with 500-nm width are fabricated from 8-nm-thick Co-Re-Pt alloy films on 1-nm-thick Ta underlayer. By injecting the current into the nanowire, the domain wall motion via depinning from extrinsic structural pinning sites is observed. The depinning time ranging over 1 mus-1 s is found to be exponentially dependent on the current density. Based on generalized Neel-Brown formula, the slope of the exponential dependence is analyzed to estimate the depinning energy barrier as a function of the current density under a constant bias magnetic field.
Keywords :
cobalt alloys; current density; ferromagnetic materials; magnetic domain walls; magnetic thin films; nanowires; perpendicular magnetic anisotropy; platinum alloys; rhenium alloys; tantalum; CoRePtJk-Ta; Neel-Brown formula; Ta; current density; current-induced domain-wall depinning; depinning; depinning energy barrier; domain wall motion; exponential dependency; extrinsic structural pinning; ferromagnetic nanowires; magnetization reversal; perpendicular magnetic anisotropy; size 1 nm; size 500 nm; spin-transfer torque; Nanowire; perpendicular magnetic anisotropy; spin-transfer torque (STT); thermally activated magnetization reversal;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2008.2002419
