Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses

K. Mitsuzuka, Nobuaki Kikuchi, T. Shimatsu, T. Shimatsu, O. Kitakami, H. Aoi, H. Muraoka, J.C. Lodder

Research output: Contribution to journalArticleAcademicpeer-review

21 Citations (Scopus)
66 Downloads (Pure)

Abstract

The switching fields and thermal stability of CoPt/Ru dot arrays with various dot thickness delta (5-20 nm) were experimentally investigated as a function of the dot diameter, D, (130-300 nm). All dot arrays showed a single domain state, even after removal of an applied field equal to the remanence coercivity Hr. The angular dependence of Hr for the dot arrays indicated coherent rotation of the magnetization during nucleation. We estimated the values of the "intrinsic" remanence coercivity H0 obtained by subtracting the effect of thermal agitation on the magnetization and the stabilizing energy barrier to nucleation E0/(kBT). The variation in H0 as a function of delta and D was qualitatively in good agreement with that of the effective anisotropy field at the dot center Hk eff(r=0), calculated taking account of the demagnetizing field in the dots. The ratio of H 0 to Hk eff(r=0) for the dot arrays with delta=10 nm increased from 0.53 to 0.70 as D decreased from 300 to 140 nm, and no significant difference in the H0/Hk eff(r=0) ratio due to the difference in delta was observed. On the other hand, E0/(k BT) decreased as delta decreased. E0/(kBT) increased slightly as D decreased, but, was not so sensitive to D over the present D range
Original languageUndefined
Article number10.1109/TMAG.2007.893129
Pages (from-to)2160-2162
Number of pages3
JournalIEEE transactions on magnetics
Volume43
Issue number6
DOIs
Publication statusPublished - 6 Jun 2007

Keywords

  • TST-SMI: Formerly in EWI-SMI
  • EWI-9812
  • IR-67103
  • METIS-241624
  • TST-LIL: Laser Interference Lithography

Cite this

Mitsuzuka, K., Kikuchi, N., Shimatsu, T., Shimatsu, T., Kitakami, O., Aoi, H., ... Lodder, J. C. (2007). Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses. IEEE transactions on magnetics, 43(6), 2160-2162. [10.1109/TMAG.2007.893129]. https://doi.org/10.1109/TMAG.2007.893129
Mitsuzuka, K. ; Kikuchi, Nobuaki ; Shimatsu, T. ; Shimatsu, T. ; Kitakami, O. ; Aoi, H. ; Muraoka, H. ; Lodder, J.C. / Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses. In: IEEE transactions on magnetics. 2007 ; Vol. 43, No. 6. pp. 2160-2162.
@article{3a00f2e03b884aef8c9b14bfbb91a563,
title = "Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses",
abstract = "The switching fields and thermal stability of CoPt/Ru dot arrays with various dot thickness delta (5-20 nm) were experimentally investigated as a function of the dot diameter, D, (130-300 nm). All dot arrays showed a single domain state, even after removal of an applied field equal to the remanence coercivity Hr. The angular dependence of Hr for the dot arrays indicated coherent rotation of the magnetization during nucleation. We estimated the values of the {"}intrinsic{"} remanence coercivity H0 obtained by subtracting the effect of thermal agitation on the magnetization and the stabilizing energy barrier to nucleation E0/(kBT). The variation in H0 as a function of delta and D was qualitatively in good agreement with that of the effective anisotropy field at the dot center Hk eff(r=0), calculated taking account of the demagnetizing field in the dots. The ratio of H 0 to Hk eff(r=0) for the dot arrays with delta=10 nm increased from 0.53 to 0.70 as D decreased from 300 to 140 nm, and no significant difference in the H0/Hk eff(r=0) ratio due to the difference in delta was observed. On the other hand, E0/(k BT) decreased as delta decreased. E0/(kBT) increased slightly as D decreased, but, was not so sensitive to D over the present D range",
keywords = "TST-SMI: Formerly in EWI-SMI, EWI-9812, IR-67103, METIS-241624, TST-LIL: Laser Interference Lithography",
author = "K. Mitsuzuka and Nobuaki Kikuchi and T. Shimatsu and T. Shimatsu and O. Kitakami and H. Aoi and H. Muraoka and J.C. Lodder",
note = "10.1109/TMAG.2007.893129",
year = "2007",
month = "6",
day = "6",
doi = "10.1109/TMAG.2007.893129",
language = "Undefined",
volume = "43",
pages = "2160--2162",
journal = "IEEE transactions on magnetics",
issn = "0018-9464",
publisher = "IEEE",
number = "6",

}

Mitsuzuka, K, Kikuchi, N, Shimatsu, T, Shimatsu, T, Kitakami, O, Aoi, H, Muraoka, H & Lodder, JC 2007, 'Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses' IEEE transactions on magnetics, vol. 43, no. 6, 10.1109/TMAG.2007.893129, pp. 2160-2162. https://doi.org/10.1109/TMAG.2007.893129

Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses. / Mitsuzuka, K.; Kikuchi, Nobuaki; Shimatsu, T.; Shimatsu, T.; Kitakami, O.; Aoi, H.; Muraoka, H.; Lodder, J.C.

In: IEEE transactions on magnetics, Vol. 43, No. 6, 10.1109/TMAG.2007.893129, 06.06.2007, p. 2160-2162.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses

AU - Mitsuzuka, K.

AU - Kikuchi, Nobuaki

AU - Shimatsu, T.

AU - Shimatsu, T.

AU - Kitakami, O.

AU - Aoi, H.

AU - Muraoka, H.

AU - Lodder, J.C.

N1 - 10.1109/TMAG.2007.893129

PY - 2007/6/6

Y1 - 2007/6/6

N2 - The switching fields and thermal stability of CoPt/Ru dot arrays with various dot thickness delta (5-20 nm) were experimentally investigated as a function of the dot diameter, D, (130-300 nm). All dot arrays showed a single domain state, even after removal of an applied field equal to the remanence coercivity Hr. The angular dependence of Hr for the dot arrays indicated coherent rotation of the magnetization during nucleation. We estimated the values of the "intrinsic" remanence coercivity H0 obtained by subtracting the effect of thermal agitation on the magnetization and the stabilizing energy barrier to nucleation E0/(kBT). The variation in H0 as a function of delta and D was qualitatively in good agreement with that of the effective anisotropy field at the dot center Hk eff(r=0), calculated taking account of the demagnetizing field in the dots. The ratio of H 0 to Hk eff(r=0) for the dot arrays with delta=10 nm increased from 0.53 to 0.70 as D decreased from 300 to 140 nm, and no significant difference in the H0/Hk eff(r=0) ratio due to the difference in delta was observed. On the other hand, E0/(k BT) decreased as delta decreased. E0/(kBT) increased slightly as D decreased, but, was not so sensitive to D over the present D range

AB - The switching fields and thermal stability of CoPt/Ru dot arrays with various dot thickness delta (5-20 nm) were experimentally investigated as a function of the dot diameter, D, (130-300 nm). All dot arrays showed a single domain state, even after removal of an applied field equal to the remanence coercivity Hr. The angular dependence of Hr for the dot arrays indicated coherent rotation of the magnetization during nucleation. We estimated the values of the "intrinsic" remanence coercivity H0 obtained by subtracting the effect of thermal agitation on the magnetization and the stabilizing energy barrier to nucleation E0/(kBT). The variation in H0 as a function of delta and D was qualitatively in good agreement with that of the effective anisotropy field at the dot center Hk eff(r=0), calculated taking account of the demagnetizing field in the dots. The ratio of H 0 to Hk eff(r=0) for the dot arrays with delta=10 nm increased from 0.53 to 0.70 as D decreased from 300 to 140 nm, and no significant difference in the H0/Hk eff(r=0) ratio due to the difference in delta was observed. On the other hand, E0/(k BT) decreased as delta decreased. E0/(kBT) increased slightly as D decreased, but, was not so sensitive to D over the present D range

KW - TST-SMI: Formerly in EWI-SMI

KW - EWI-9812

KW - IR-67103

KW - METIS-241624

KW - TST-LIL: Laser Interference Lithography

U2 - 10.1109/TMAG.2007.893129

DO - 10.1109/TMAG.2007.893129

M3 - Article

VL - 43

SP - 2160

EP - 2162

JO - IEEE transactions on magnetics

JF - IEEE transactions on magnetics

SN - 0018-9464

IS - 6

M1 - 10.1109/TMAG.2007.893129

ER -

Mitsuzuka K, Kikuchi N, Shimatsu T, Shimatsu T, Kitakami O, Aoi H et al. Switching field and thermal stability of CoPt/Ru dot arrays with various thicknesses. IEEE transactions on magnetics. 2007 Jun 6;43(6):2160-2162. 10.1109/TMAG.2007.893129. https://doi.org/10.1109/TMAG.2007.893129