High temperature annealing induced superparamagnetism in CoFeB/MgO/CoFeB tunneling junctions

Xiaoming Kou, Weigang Wang, Xin Fan, Lubna R. Shah, Rae Tao, John Q. Xiao

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We have investigated the evolution of the magnetic transport properties as a function of short annealing time in CoFeB/MgO/CoFeB based magnetic tunnel junctions (MTJs) with a free layer of 2 nm. It is found that the hysteresis behaviors in magnetoresistance (MR) loops disappear in samples annealed for 17 min. The linear region between MR and the applied field gradually increases. The MR loops without hysteresis can be well fitted by using the superparamagnetism theory, suggesting the formation of superparamagnetic particles in the free layer during the high temperature annealing. The control of MTJ properties with annealing time is desirable in magnetic field sensor productions.

Original languageEnglish (US)
Article number083901
JournalJournal of Applied Physics
Volume108
Issue number8
DOIs
StatePublished - Oct 15 2010
Externally publishedYes

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tunnel junctions
annealing
hysteresis
transport properties
sensors
magnetic fields

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

High temperature annealing induced superparamagnetism in CoFeB/MgO/CoFeB tunneling junctions. / Kou, Xiaoming; Wang, Weigang; Fan, Xin; Shah, Lubna R.; Tao, Rae; Xiao, John Q.

In: Journal of Applied Physics, Vol. 108, No. 8, 083901, 15.10.2010.

Research output: Contribution to journalArticle

Kou, Xiaoming ; Wang, Weigang ; Fan, Xin ; Shah, Lubna R. ; Tao, Rae ; Xiao, John Q. / High temperature annealing induced superparamagnetism in CoFeB/MgO/CoFeB tunneling junctions. In: Journal of Applied Physics. 2010 ; Vol. 108, No. 8.
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AU - Xiao, John Q.

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