DocumentCode
69341
Title
Development of Spin-Torque Oscillators and High 
CoPt Media With Small Grain Size for Microwave-Assisted Magnetic Recording
Author
Tiejun Zhou ; Mingsheng Zhang ; Kiat Min Cher ; Hon Seng Wong ; Hong Jing Chung ; Boon Hao Low ; Yi Yang ; Zhejie Liu ; Tjiptoharsono, Febiana
Author_Institution
Data Storage Inst., Agency for Sci. Technol. & Res., Singapore, Singapore
Volume
51
Issue
4
fYear
2015
fDate
Apr-15
Firstpage
1
Lastpage
7
Abstract
We report the selection of materials and design of spin-torque oscillators (STOs) which are able to operate in an alternative magnetic field (variable frequency) of magnitude ~8000 Oe, generate large enough in-plane ac magnetic field in the recording media, and have tunable high frequency at low driving current for microwave-assisted magnetic recording (MAMR) based on micromagnetic simulations. The mechanism and integration approaches of STOs with the current recording system to have the least driving current are also presented. This paper also covers the material choice, layer-stack optimization, and process development on Cox Pt1-x alloy films with extremely high coercivity of more than 1.5 T (Ku of about 1.5 × 107 erg/cc), well-isolated small grains of size 6-7 nm, for the extension of perpendicular magnetic recording and MAMR.
Keywords
cobalt alloys; coercive force; grain size; integration; magnetic thin films; metallic thin films; micromagnetics; oscillators; perpendicular magnetic recording; platinum alloys; CoPt; CoPt media; alloy films; coercivity; driving current; grain size; in-plane ac magnetic field; integration approaches; layer-stack optimization; material selection; micromagnetic simulations; microwave-assisted magnetic recording; perpendicular magnetic recording extension; size 6 nm to 7 nm; spin-torque oscillator design; tunable frequency; well-isolated small grains; Anisotropic magnetoresistance; Damping; Magnetic heads; Magnetic recording; Magnetization; Media; Switches; Anisotropy energy; CoPt; composite reference layer; magnetization precession; microwave assisted magnetic recording (MAMR); spin-torque oscillator (STO);
fLanguage
English
Journal_Title
Magnetics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9464
Type
jour
DOI
10.1109/TMAG.2014.2354411
Filename
7109982
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