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

Volume

44

Issue

11

fYear

2008

Firstpage

2531

Lastpage

2534

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2008.2002419

Filename

4717721