Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB

J. R. Rhee, J. Y. Hwang, S. S. Kim, M. Y. Kim, B. S. Chun, I. S. Yoo, B. S. Oh, Young-geun Kim, T. W. Kim, W. J. Park

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Magnetic tunnel junctions (MTJs), which consisted of amorphous CoFeSiB layers, were investigated. The CoFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with an emphasis given on understanding the effect of the amorphous free layer on the switching characteristics of the MTJs. CoFeSiB has a lower saturation magnetization (Ms : 560 emu/cm3) and a higher anisotropy constant (Ku : 2 800 erg/cm3) than CoFe and NiFe, respectively. An exchange coupling energy (Jex) of -0.003 erg/cm2 was observed by inserting a 1.0 nm Ru layer in between CoFeSiB layers. In the Si-SiO2-Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlOx/CoFeSiB 7 or CoFeSiB (t)/Ru 1.0/CoFeSiB (7-t)/Ru 60 (in nanometers) MTJs structure, it was found that the size dependence of the switching field originated in the lower Jex using the experimental and simulation results. The CoFeSiB synthetic antiferromagnet structures were proved to be beneficial for the switching characteristics such as reducing the coercivity (Hc) and increasing the sensitivity in micrometer size, even in submicrometer sized elements.

Original languageEnglish
Pages (from-to)2685-2687
Number of pages3
JournalIEEE Transactions on Magnetics
Volume41
Issue number10
DOIs
Publication statusPublished - 2005 Oct 1
Externally publishedYes

Fingerprint

Tunnelling magnetoresistance
Tunnel junctions
tunnel junctions
Magnetization
magnetization
Exchange coupling
Saturation magnetization
Coercive force
Anisotropy
coercivity
micrometers
substitutes
saturation
anisotropy
sensitivity

Keywords

  • Amorphous ferromagnet
  • CoFeSiB
  • Magnetic random access memory (MRAM)
  • Switching field
  • Synthetic antiferromagnet (SAF)
  • Tunneling magnetoresistance (TMR)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)

Cite this

Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB. / Rhee, J. R.; Hwang, J. Y.; Kim, S. S.; Kim, M. Y.; Chun, B. S.; Yoo, I. S.; Oh, B. S.; Kim, Young-geun; Kim, T. W.; Park, W. J.

In: IEEE Transactions on Magnetics, Vol. 41, No. 10, 01.10.2005, p. 2685-2687.

Research output: Contribution to journalArticle

Rhee, J. R. ; Hwang, J. Y. ; Kim, S. S. ; Kim, M. Y. ; Chun, B. S. ; Yoo, I. S. ; Oh, B. S. ; Kim, Young-geun ; Kim, T. W. ; Park, W. J. / Magnetization switching and tunneling magnetoresistance effects of MTJs with synthetic antiferromagnet free layers consisting of amorphous CoFeSiB. In: IEEE Transactions on Magnetics. 2005 ; Vol. 41, No. 10. pp. 2685-2687.
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