TY - JOUR

T1 - Magnetic anisotropy in antiferromagnetic layers affecting exchange bias of Ni–Fe/Mn–Ir bilayers

AU - Yagami, Kojiro

AU - Tsunoda, Masakiyo

AU - Takahashi, Migaku

PY - 2000/5/1

Y1 - 2000/5/1

N2 - The magnetic anisotropy of antiferromagnetic layers [formula omitted] was estimated for Ni–Fe 50 Å/Mn–Ir [formula omitted] bilayers using Mauri's method [formula omitted] where [formula omitted] is the saturation value of the unidirectional anisotropy constant [formula omitted] The critical thickness of the antiferromagnetic layers [formula omitted] at which [formula omitted] took half the value of [formula omitted] was determined from the dependence of [formula omitted] on [formula omitted] The [formula omitted] was found to be almost constant [formula omitted] independent of [formula omitted] Thus, the relation of [formula omitted] was derived, suggesting that the variation in [formula omitted] is due to a change in the value of [formula omitted] [formula omitted] however, was found to vary considerably for various Mn–Ir films possessing an almost identical Ir content, and thus probably the same value of [formula omitted] In addition, studies by x-ray diffraction, transmission electron microscopy, and electron diffraction revealed that the change in [formula omitted] was independent of the microstructure and phase of the antiferromagnetic (AF) Mn–Ir films, both of which control [formula omitted] Thus, [formula omitted] was found to be independent of [formula omitted] contradicting the relation, [formula omitted] This contradiction results from the assumption by Mauri that the coupling energy (J) is equal to [formula omitted] even in the polycrystalline exchange-coupled bilayers. A model that took account of the distribution of [formula omitted] axes of AF grains in the plane of the AF film successfully explained the behavior of [formula omitted] [formula omitted] was found to change independent of both J and [formula omitted] and furthermore, it has been shown that the dependence of [formula omitted] on the sputtering conditions for Mn–Ir films is probably due to the effective temperature of the films during deposition.

AB - The magnetic anisotropy of antiferromagnetic layers [formula omitted] was estimated for Ni–Fe 50 Å/Mn–Ir [formula omitted] bilayers using Mauri's method [formula omitted] where [formula omitted] is the saturation value of the unidirectional anisotropy constant [formula omitted] The critical thickness of the antiferromagnetic layers [formula omitted] at which [formula omitted] took half the value of [formula omitted] was determined from the dependence of [formula omitted] on [formula omitted] The [formula omitted] was found to be almost constant [formula omitted] independent of [formula omitted] Thus, the relation of [formula omitted] was derived, suggesting that the variation in [formula omitted] is due to a change in the value of [formula omitted] [formula omitted] however, was found to vary considerably for various Mn–Ir films possessing an almost identical Ir content, and thus probably the same value of [formula omitted] In addition, studies by x-ray diffraction, transmission electron microscopy, and electron diffraction revealed that the change in [formula omitted] was independent of the microstructure and phase of the antiferromagnetic (AF) Mn–Ir films, both of which control [formula omitted] Thus, [formula omitted] was found to be independent of [formula omitted] contradicting the relation, [formula omitted] This contradiction results from the assumption by Mauri that the coupling energy (J) is equal to [formula omitted] even in the polycrystalline exchange-coupled bilayers. A model that took account of the distribution of [formula omitted] axes of AF grains in the plane of the AF film successfully explained the behavior of [formula omitted] [formula omitted] was found to change independent of both J and [formula omitted] and furthermore, it has been shown that the dependence of [formula omitted] on the sputtering conditions for Mn–Ir films is probably due to the effective temperature of the films during deposition.

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U2 - 10.1063/1.373206

DO - 10.1063/1.373206

M3 - Article

AN - SCOPUS:0012048789

VL - 87

SP - 4930

EP - 4932

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 9

ER -