Development of spin-torque oscillators and high CoPt media with small grain size for microwave-assisted magnetic recording

Tiejun Zhou, Mingsheng Zhang, Kiat Min Cher, Hon Seng Wong, Hong Jing Chung, Boon Hao Low, Yi Yang, Zhejie Liu, Febiana Tjiptoharsono

Research output: Contribution to journalArticle

5 Citations (Scopus)

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 $\sim 8000$ 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 Co<inf>x</inf> Pt<inf>1-x</inf> alloy films with extremely high coercivity of more than 1.5 T ( $K-{u}$ of about $\mathbf {1.5\times 10^{7}}$ erg/cc), well-isolated small grains of size 6-7 nm, for the extension of perpendicular magnetic recording and MAMR.

Original languageEnglish
Article number7109982
JournalIEEE Transactions on Magnetics
Volume51
Issue number4
DOIs
Publication statusPublished - 1 Apr 2015
Externally publishedYes

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Magnetic recording
Torque
Microwaves
Magnetic fields
Coercive force

Keywords

  • Anisotropy energy
  • composite reference layer
  • CoPt
  • magnetization precession
  • microwave assisted magnetic recording (MAMR)
  • spin-torque oscillator (STO)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

Development of spin-torque oscillators and high CoPt media with small grain size for microwave-assisted magnetic recording. / Zhou, Tiejun; Zhang, Mingsheng; Cher, Kiat Min; Wong, Hon Seng; Chung, Hong Jing; Low, Boon Hao; Yang, Yi; Liu, Zhejie; Tjiptoharsono, Febiana.

In: IEEE Transactions on Magnetics, Vol. 51, No. 4, 7109982, 01.04.2015.

Research output: Contribution to journalArticle

Zhou, T, Zhang, M, Cher, KM, Wong, HS, Chung, HJ, Low, BH, Yang, Y, Liu, Z & Tjiptoharsono, F 2015, 'Development of spin-torque oscillators and high CoPt media with small grain size for microwave-assisted magnetic recording', IEEE Transactions on Magnetics, vol. 51, no. 4, 7109982. https://doi.org/10.1109/TMAG.2014.2354411
Zhou, Tiejun ; Zhang, Mingsheng ; Cher, Kiat Min ; Wong, Hon Seng ; Chung, Hong Jing ; Low, Boon Hao ; Yang, Yi ; Liu, Zhejie ; Tjiptoharsono, Febiana. / Development of spin-torque oscillators and high CoPt media with small grain size for microwave-assisted magnetic recording. In: IEEE Transactions on Magnetics. 2015 ; Vol. 51, No. 4.
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