Exchange bias and magnetization process of Co/CoO nanocomposite thin films

J. B. Yi; J. Ding; B. H. Liu; Z. L. Dong; T. White; Y. Liu

doi:10.1016/j.jmmm.2004.07.044

Exchange bias and magnetization process of Co/CoO nanocomposite thin films

J. B. Yi^*, J. Ding, B. H. Liu, Z. L. Dong, T. White, Y. Liu

^*Corresponding author for this work

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

22 Citations (Scopus)

Abstract

Co/CoO nanocomposite thin films have been deposited by RF sputtering with different oxygen partial pressures in the working atmosphere. It has been found that the magnetic properties (exchange bias (EB), coercivity and remanence) of the films are strongly dependent on the oxygen partial pressure. Film deposited with an O₂ pressure of 0.75 × 10^-5Torr shows a relatively high coercivity and high remanence ratio. Enhanced asymmetry of magnetization reversal appears in the film deposited with 1.5 & 10 ^-5Torr O₂ partial pressure. When the O₂ partial pressure is increased to 3.0 & 10^-5Torr, a strong reduction in EB and coercivity have been obtained. The investigation of the microstructure using high-resolution transmission electron microscope reveals that the change in EB, remanence and coercivity is probably related to the competition between dipolar interaction and exchange coupling. Magnetoresistance and extraordinary Hall effect (EHE) of the Co/CoO nanocomposite films is also investigated in dependence on oxygen partial pressure. The film deposited under 2.3 × 10^-5Torr of oxygen exhibits strongly enhanced asymmetric magnetization reversal and unusually high EHE with a high coercivity.

Original language	English
Pages (from-to)	224-232
Number of pages	9
Journal	Journal of Magnetism and Magnetic Materials
Volume	285
Issue number	1-2
DOIs	https://doi.org/10.1016/j.jmmm.2004.07.044
Publication status	Published - Jan 2005
Externally published	Yes

ASJC Scopus Subject Areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics

Keywords

Asymmetric reversal
CoO/Co nanocomposite
Exchange bias
Extraordinary Hall effect
Magnetoresistance

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10.1016/j.jmmm.2004.07.044

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title = "Exchange bias and magnetization process of Co/CoO nanocomposite thin films",

abstract = "Co/CoO nanocomposite thin films have been deposited by RF sputtering with different oxygen partial pressures in the working atmosphere. It has been found that the magnetic properties (exchange bias (EB), coercivity and remanence) of the films are strongly dependent on the oxygen partial pressure. Film deposited with an O2 pressure of 0.75 × 10-5Torr shows a relatively high coercivity and high remanence ratio. Enhanced asymmetry of magnetization reversal appears in the film deposited with 1.5 & 10 -5Torr O2 partial pressure. When the O2 partial pressure is increased to 3.0 & 10-5Torr, a strong reduction in EB and coercivity have been obtained. The investigation of the microstructure using high-resolution transmission electron microscope reveals that the change in EB, remanence and coercivity is probably related to the competition between dipolar interaction and exchange coupling. Magnetoresistance and extraordinary Hall effect (EHE) of the Co/CoO nanocomposite films is also investigated in dependence on oxygen partial pressure. The film deposited under 2.3 × 10-5Torr of oxygen exhibits strongly enhanced asymmetric magnetization reversal and unusually high EHE with a high coercivity.",

keywords = "Asymmetric reversal, CoO/Co nanocomposite, Exchange bias, Extraordinary Hall effect, Magnetoresistance",

author = "Yi, {J. B.} and J. Ding and Liu, {B. H.} and Dong, {Z. L.} and T. White and Y. Liu",

year = "2005",

month = jan,

doi = "10.1016/j.jmmm.2004.07.044",

language = "English",

volume = "285",

pages = "224--232",

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TY - JOUR

T1 - Exchange bias and magnetization process of Co/CoO nanocomposite thin films

AU - Yi, J. B.

AU - Ding, J.

AU - Liu, B. H.

AU - Dong, Z. L.

AU - White, T.

AU - Liu, Y.

PY - 2005/1

Y1 - 2005/1

N2 - Co/CoO nanocomposite thin films have been deposited by RF sputtering with different oxygen partial pressures in the working atmosphere. It has been found that the magnetic properties (exchange bias (EB), coercivity and remanence) of the films are strongly dependent on the oxygen partial pressure. Film deposited with an O2 pressure of 0.75 × 10-5Torr shows a relatively high coercivity and high remanence ratio. Enhanced asymmetry of magnetization reversal appears in the film deposited with 1.5 & 10 -5Torr O2 partial pressure. When the O2 partial pressure is increased to 3.0 & 10-5Torr, a strong reduction in EB and coercivity have been obtained. The investigation of the microstructure using high-resolution transmission electron microscope reveals that the change in EB, remanence and coercivity is probably related to the competition between dipolar interaction and exchange coupling. Magnetoresistance and extraordinary Hall effect (EHE) of the Co/CoO nanocomposite films is also investigated in dependence on oxygen partial pressure. The film deposited under 2.3 × 10-5Torr of oxygen exhibits strongly enhanced asymmetric magnetization reversal and unusually high EHE with a high coercivity.

AB - Co/CoO nanocomposite thin films have been deposited by RF sputtering with different oxygen partial pressures in the working atmosphere. It has been found that the magnetic properties (exchange bias (EB), coercivity and remanence) of the films are strongly dependent on the oxygen partial pressure. Film deposited with an O2 pressure of 0.75 × 10-5Torr shows a relatively high coercivity and high remanence ratio. Enhanced asymmetry of magnetization reversal appears in the film deposited with 1.5 & 10 -5Torr O2 partial pressure. When the O2 partial pressure is increased to 3.0 & 10-5Torr, a strong reduction in EB and coercivity have been obtained. The investigation of the microstructure using high-resolution transmission electron microscope reveals that the change in EB, remanence and coercivity is probably related to the competition between dipolar interaction and exchange coupling. Magnetoresistance and extraordinary Hall effect (EHE) of the Co/CoO nanocomposite films is also investigated in dependence on oxygen partial pressure. The film deposited under 2.3 × 10-5Torr of oxygen exhibits strongly enhanced asymmetric magnetization reversal and unusually high EHE with a high coercivity.

KW - Asymmetric reversal

KW - CoO/Co nanocomposite

KW - Exchange bias

KW - Extraordinary Hall effect

KW - Magnetoresistance

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Exchange bias and magnetization process of Co/CoO nanocomposite thin films

Abstract

ASJC Scopus Subject Areas

Keywords

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