Asymmetric magnetic disorder observed in thermally activated magnetization reversal of exchange-biased IrMn/CoFe films

Hun Sung Lee; Kwang Su Ryu; Chun Yeol You; Kun Rok Jeon; See Hun Yang; Stuart S.P. Parkin; Sung Chul Shin

doi:10.1016/j.jmmm.2012.07.038

Asymmetric magnetic disorder observed in thermally activated magnetization reversal of exchange-biased IrMn/CoFe films

Hun Sung Lee, Kwang Su Ryu, Chun Yeol You, Kun Rok Jeon, See Hun Yang, Stuart S.P. Parkin, Sung Chul Shin

Department of Physics and Chemistry

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

We report an asymmetry of magnetic disorder in exchange-biased IrMn(t _IrMn=5-20 nm)/CoFe(50 nm) films observed by means of a Kerr microscope, capable of direct domain observation. From the correlation between the magnetization half-reversal time and applied magnetic field, we find that the magnetization switching in all the films occurs via a thermally activated reversal mechanism for both branches of hysteresis loops. Surprisingly, in the forward branch reversal where the applied magnetic field is antiparallel to the direction of exchange-bias field, degree of magnetic disorder decreases as exchange-bias field increases, which is definitely contrasted with the case of backward branch reversal. This result is likely ascribed to the fact that the local values of exchange-bias field and coercive field are oppositely fluctuating with each other in the film.

Original language	English
Pages (from-to)	13-16
Number of pages	4
Journal	Journal of Magnetism and Magnetic Materials
Volume	325
DOIs	https://doi.org/10.1016/j.jmmm.2012.07.038
State	Published - Jan 2013

Bibliographical note

Funding Information:
This work was supported by the National Research Laboratory Program (Contract no. R0A-2007-000-20026-0 ) and ( 2010-0022040 and 2010-0023798 ) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology . H.-S. Lee would like to thank Donghwa Sanup Scholarship Foundation for financial support .

Keywords

Asymmetry
Domain wall motion
Exchange-bias
Magnetic disorder
Thermally activated reversal behavior

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10.1016/j.jmmm.2012.07.038

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title = "Asymmetric magnetic disorder observed in thermally activated magnetization reversal of exchange-biased IrMn/CoFe films",

abstract = "We report an asymmetry of magnetic disorder in exchange-biased IrMn(t IrMn=5-20 nm)/CoFe(50 nm) films observed by means of a Kerr microscope, capable of direct domain observation. From the correlation between the magnetization half-reversal time and applied magnetic field, we find that the magnetization switching in all the films occurs via a thermally activated reversal mechanism for both branches of hysteresis loops. Surprisingly, in the forward branch reversal where the applied magnetic field is antiparallel to the direction of exchange-bias field, degree of magnetic disorder decreases as exchange-bias field increases, which is definitely contrasted with the case of backward branch reversal. This result is likely ascribed to the fact that the local values of exchange-bias field and coercive field are oppositely fluctuating with each other in the film.",

keywords = "Asymmetry, Domain wall motion, Exchange-bias, Magnetic disorder, Thermally activated reversal behavior",

author = "Lee, {Hun Sung} and Ryu, {Kwang Su} and You, {Chun Yeol} and Jeon, {Kun Rok} and Yang, {See Hun} and Parkin, {Stuart S.P.} and Shin, {Sung Chul}",

note = "Funding Information: This work was supported by the National Research Laboratory Program (Contract no. R0A-2007-000-20026-0 ) and ( 2010-0022040 and 2010-0023798 ) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology . H.-S. Lee would like to thank Donghwa Sanup Scholarship Foundation for financial support .",

year = "2013",

month = jan,

doi = "10.1016/j.jmmm.2012.07.038",

language = "English",

volume = "325",

pages = "13--16",

journal = "Journal of Magnetism and Magnetic Materials",

issn = "0304-8853",

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TY - JOUR

T1 - Asymmetric magnetic disorder observed in thermally activated magnetization reversal of exchange-biased IrMn/CoFe films

AU - Lee, Hun Sung

AU - Ryu, Kwang Su

AU - You, Chun Yeol

AU - Jeon, Kun Rok

AU - Yang, See Hun

AU - Parkin, Stuart S.P.

AU - Shin, Sung Chul

N1 - Funding Information: This work was supported by the National Research Laboratory Program (Contract no. R0A-2007-000-20026-0 ) and ( 2010-0022040 and 2010-0023798 ) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology . H.-S. Lee would like to thank Donghwa Sanup Scholarship Foundation for financial support .

PY - 2013/1

Y1 - 2013/1

N2 - We report an asymmetry of magnetic disorder in exchange-biased IrMn(t IrMn=5-20 nm)/CoFe(50 nm) films observed by means of a Kerr microscope, capable of direct domain observation. From the correlation between the magnetization half-reversal time and applied magnetic field, we find that the magnetization switching in all the films occurs via a thermally activated reversal mechanism for both branches of hysteresis loops. Surprisingly, in the forward branch reversal where the applied magnetic field is antiparallel to the direction of exchange-bias field, degree of magnetic disorder decreases as exchange-bias field increases, which is definitely contrasted with the case of backward branch reversal. This result is likely ascribed to the fact that the local values of exchange-bias field and coercive field are oppositely fluctuating with each other in the film.

AB - We report an asymmetry of magnetic disorder in exchange-biased IrMn(t IrMn=5-20 nm)/CoFe(50 nm) films observed by means of a Kerr microscope, capable of direct domain observation. From the correlation between the magnetization half-reversal time and applied magnetic field, we find that the magnetization switching in all the films occurs via a thermally activated reversal mechanism for both branches of hysteresis loops. Surprisingly, in the forward branch reversal where the applied magnetic field is antiparallel to the direction of exchange-bias field, degree of magnetic disorder decreases as exchange-bias field increases, which is definitely contrasted with the case of backward branch reversal. This result is likely ascribed to the fact that the local values of exchange-bias field and coercive field are oppositely fluctuating with each other in the film.

KW - Asymmetry

KW - Domain wall motion

KW - Exchange-bias

KW - Magnetic disorder

KW - Thermally activated reversal behavior

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U2 - 10.1016/j.jmmm.2012.07.038

DO - 10.1016/j.jmmm.2012.07.038

M3 - Article

AN - SCOPUS:84867301351

SN - 0304-8853

VL - 325

SP - 13

EP - 16

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

ER -

Asymmetric magnetic disorder observed in thermally activated magnetization reversal of exchange-biased IrMn/CoFe films

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Keywords

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