Sharrock Relation for Perpendicular Recording Media with Higher-Order Magnetic Anisotropy Terms

Osamu Kitakami; Takehito Shimatsu; Satoshi Okamoto; Yutaka Shimada; Hajime Aoi

doi:10.1143/JJAP.43.L115

Sharrock Relation for Perpendicular Recording Media with Higher-Order Magnetic Anisotropy Terms

Osamu Kitakami, Takehito Shimatsu, Satoshi Okamoto, Yutaka Shimada, Hajime Aoi

Tohoku University

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

11 Citations (Scopus)

Abstract

Based on the Stoner-Wohlfarth model, we have studied the effects of higher order magnetic anisotropy terms on the dynamic coercivity of perpendicular magnetic recording media. The waiting time dependence of the dynamic coercivity H_c becomes very gradual due to the presence of the second-order anisotropy constant, reflecting the fact that the higher-order anisotropy appreciably enhances the energy barrier for thermal stability. It is found that the behavior of H_c can be perfectly described by modifying the well-known Sharrock formula as H_c = H_K {1 - [(k _BT/K*V)ln(f₀t′/ln2)]ⁿ} and the higher-order anisotropy term appreciably enhances both the effective anisotropy constant K* and the index n.

Original language	English
Pages (from-to)	L115-L117
Journal	Japanese Journal of Applied Physics
Volume	43
Issue number	1 A/B
DOIs	https://doi.org/10.1143/JJAP.43.L115
Publication status	Published - 2004 Jan 15

Keywords

Dynamic coercivity
Energy barrier
Magnetic anisotropy
Magnetization dynamics
Saturation recording
Thermal stability

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10.1143/JJAP.43.L115

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abstract = "Based on the Stoner-Wohlfarth model, we have studied the effects of higher order magnetic anisotropy terms on the dynamic coercivity of perpendicular magnetic recording media. The waiting time dependence of the dynamic coercivity Hc becomes very gradual due to the presence of the second-order anisotropy constant, reflecting the fact that the higher-order anisotropy appreciably enhances the energy barrier for thermal stability. It is found that the behavior of Hc can be perfectly described by modifying the well-known Sharrock formula as Hc = HK {1 - [(k BT/K*V)ln(f0t′/ln2)]n} and the higher-order anisotropy term appreciably enhances both the effective anisotropy constant K* and the index n.",

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AU - Kitakami, Osamu

AU - Shimatsu, Takehito

AU - Okamoto, Satoshi

AU - Shimada, Yutaka

AU - Aoi, Hajime

PY - 2004/1/15

Y1 - 2004/1/15

N2 - Based on the Stoner-Wohlfarth model, we have studied the effects of higher order magnetic anisotropy terms on the dynamic coercivity of perpendicular magnetic recording media. The waiting time dependence of the dynamic coercivity Hc becomes very gradual due to the presence of the second-order anisotropy constant, reflecting the fact that the higher-order anisotropy appreciably enhances the energy barrier for thermal stability. It is found that the behavior of Hc can be perfectly described by modifying the well-known Sharrock formula as Hc = HK {1 - [(k BT/K*V)ln(f0t′/ln2)]n} and the higher-order anisotropy term appreciably enhances both the effective anisotropy constant K* and the index n.

AB - Based on the Stoner-Wohlfarth model, we have studied the effects of higher order magnetic anisotropy terms on the dynamic coercivity of perpendicular magnetic recording media. The waiting time dependence of the dynamic coercivity Hc becomes very gradual due to the presence of the second-order anisotropy constant, reflecting the fact that the higher-order anisotropy appreciably enhances the energy barrier for thermal stability. It is found that the behavior of Hc can be perfectly described by modifying the well-known Sharrock formula as Hc = HK {1 - [(k BT/K*V)ln(f0t′/ln2)]n} and the higher-order anisotropy term appreciably enhances both the effective anisotropy constant K* and the index n.

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KW - Energy barrier

KW - Magnetic anisotropy

KW - Magnetization dynamics

KW - Saturation recording

KW - Thermal stability

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Sharrock Relation for Perpendicular Recording Media with Higher-Order Magnetic Anisotropy Terms

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Keywords

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