Thermally activated magnetization reversal in exchange-biased [Pt∕Co]3/Pt/IrMn multilayers

M. Czapkiewicz (Corresponding Author), T. Stobiecki, Sebastiaan van Dijken

Research output: Contribution to journalArticleScientificpeer-review

21 Citations (Scopus)

Abstract

We report on the magnetization reversal in exchange-biased [Pt∕Co]3/t Pt∕IrMn multilayers with different Pt insertion layer thicknesses (0 ≤ t ≤ 1.2 nm). For t=0 nm and t=0.2–0.8 nm, magnetization reversal is asymmetric and proceeds by domain nucleation followed by a fast domain wall motion. For t=0.1 nm, domain nucleation is predominant. We interpret these results within a model for thermally activated reversal where a dispersion of the activation energy barrier is specifically taken into account. From magnetization relaxation curves, we are able to measure the barrier dispersion and identify the physical origin of different reversal effects: whereas reversal asymmetry is mostly due to local fluctuations of the anisotropy axis and exchange bias direction, the nucleation of a large number of inverse domains is caused by lateral variations of the interface exchange coupling energy. Moreover, we show that an improved perpendicular spin alignment in the outermost Co film maximizes the exchange coupling energy for a Pt insertion layer of 0.1 nm.
Original languageEnglish
Article number024416
JournalPhysical Review B: Condensed Matter and Materials Physics
Volume77
Issue number2
DOIs
Publication statusPublished - 2008
MoE publication typeA1 Journal article-refereed

Fingerprint

Magnetization reversal
Exchange coupling
Multilayers
Nucleation
nucleation
magnetization
insertion
Energy barriers
Domain walls
domain wall
Magnetization
Anisotropy
Activation energy
alignment
asymmetry
activation energy
anisotropy
energy
curves

Keywords

  • cobalt
  • exchange interactions
  • iridium alloys
  • iridium
  • magnetic anisotropy
  • magnetic domains
  • magnetic multilayers
  • magnetisation reversal
  • magnetisation curves
  • magnetisation
  • manganese alloys
  • nucleation
  • platinum

Cite this

@article{f2fd0d88f6f049c0b612c55ec0dd924b,
title = "Thermally activated magnetization reversal in exchange-biased [Pt∕Co]3/Pt/IrMn multilayers",
abstract = "We report on the magnetization reversal in exchange-biased [Pt∕Co]3/t Pt∕IrMn multilayers with different Pt insertion layer thicknesses (0 ≤ t ≤ 1.2 nm). For t=0 nm and t=0.2–0.8 nm, magnetization reversal is asymmetric and proceeds by domain nucleation followed by a fast domain wall motion. For t=0.1 nm, domain nucleation is predominant. We interpret these results within a model for thermally activated reversal where a dispersion of the activation energy barrier is specifically taken into account. From magnetization relaxation curves, we are able to measure the barrier dispersion and identify the physical origin of different reversal effects: whereas reversal asymmetry is mostly due to local fluctuations of the anisotropy axis and exchange bias direction, the nucleation of a large number of inverse domains is caused by lateral variations of the interface exchange coupling energy. Moreover, we show that an improved perpendicular spin alignment in the outermost Co film maximizes the exchange coupling energy for a Pt insertion layer of 0.1 nm.",
keywords = "cobalt, exchange interactions, iridium alloys, iridium, magnetic anisotropy, magnetic domains, magnetic multilayers, magnetisation reversal, magnetisation curves, magnetisation, manganese alloys, nucleation, platinum",
author = "M. Czapkiewicz and T. Stobiecki and {van Dijken}, Sebastiaan",
year = "2008",
doi = "10.1103/PhysRevB.77.024416",
language = "English",
volume = "77",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
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Thermally activated magnetization reversal in exchange-biased [Pt∕Co]3/Pt/IrMn multilayers. / Czapkiewicz, M. (Corresponding Author); Stobiecki, T.; van Dijken, Sebastiaan.

In: Physical Review B: Condensed Matter and Materials Physics, Vol. 77, No. 2, 024416, 2008.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Thermally activated magnetization reversal in exchange-biased [Pt∕Co]3/Pt/IrMn multilayers

AU - Czapkiewicz, M.

AU - Stobiecki, T.

AU - van Dijken, Sebastiaan

PY - 2008

Y1 - 2008

N2 - We report on the magnetization reversal in exchange-biased [Pt∕Co]3/t Pt∕IrMn multilayers with different Pt insertion layer thicknesses (0 ≤ t ≤ 1.2 nm). For t=0 nm and t=0.2–0.8 nm, magnetization reversal is asymmetric and proceeds by domain nucleation followed by a fast domain wall motion. For t=0.1 nm, domain nucleation is predominant. We interpret these results within a model for thermally activated reversal where a dispersion of the activation energy barrier is specifically taken into account. From magnetization relaxation curves, we are able to measure the barrier dispersion and identify the physical origin of different reversal effects: whereas reversal asymmetry is mostly due to local fluctuations of the anisotropy axis and exchange bias direction, the nucleation of a large number of inverse domains is caused by lateral variations of the interface exchange coupling energy. Moreover, we show that an improved perpendicular spin alignment in the outermost Co film maximizes the exchange coupling energy for a Pt insertion layer of 0.1 nm.

AB - We report on the magnetization reversal in exchange-biased [Pt∕Co]3/t Pt∕IrMn multilayers with different Pt insertion layer thicknesses (0 ≤ t ≤ 1.2 nm). For t=0 nm and t=0.2–0.8 nm, magnetization reversal is asymmetric and proceeds by domain nucleation followed by a fast domain wall motion. For t=0.1 nm, domain nucleation is predominant. We interpret these results within a model for thermally activated reversal where a dispersion of the activation energy barrier is specifically taken into account. From magnetization relaxation curves, we are able to measure the barrier dispersion and identify the physical origin of different reversal effects: whereas reversal asymmetry is mostly due to local fluctuations of the anisotropy axis and exchange bias direction, the nucleation of a large number of inverse domains is caused by lateral variations of the interface exchange coupling energy. Moreover, we show that an improved perpendicular spin alignment in the outermost Co film maximizes the exchange coupling energy for a Pt insertion layer of 0.1 nm.

KW - cobalt

KW - exchange interactions

KW - iridium alloys

KW - iridium

KW - magnetic anisotropy

KW - magnetic domains

KW - magnetic multilayers

KW - magnetisation reversal

KW - magnetisation curves

KW - magnetisation

KW - manganese alloys

KW - nucleation

KW - platinum

U2 - 10.1103/PhysRevB.77.024416

DO - 10.1103/PhysRevB.77.024416

M3 - Article

VL - 77

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

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