Synthesis of Co100-xPtx alloy fine particles with high coercivity

Takahiro Ibusuki; Tomoaki Sakurai; Osamu Kitakami; Yutaka Shimada

doi:10.1109/20.950822

Synthesis of Co_100-xPt_x alloy fine particles with high coercivity

Takahiro Ibusuki, Tomoaki Sakurai, Osamu Kitakami, Yutaka Shimada

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

3 Citations (Scopus)

Abstract

In the present study, we have prepared and investigated Co_100-xPt_x (0 ≤ x ≤ 40) fine particles with the average diameter of D = 3 ∼ 40nm. At a fixed D ∼ 10 nm, the room temperature coercivity H_c increases with the Pt content x and takes a maximum value of 1000 Oe at x ∼ 25 at.% for 3D random assemblies of the particles. Such remarkable enhancement of the coercivity due to Pt is attributed to very strong magnetic anisotropy, as evaluated by the law of approach to saturation. At x ∼ 25 at.%, H_c increases with D due to suppression of thermal agitation and takes a maximum of 4000 Oe around at D ∼ 15 nm. Micromagnetic calculations taking into account dipolar interactions between particles have verified that the magnetic behaviours of Co₇₅Pt₂₅ fine particles can be explained by the coherent rotation model.

Original language	English
Pages (from-to)	1295-1298
Number of pages	4
Journal	IEEE Transactions on Magnetics
Volume	37
Issue number	4
DOIs	https://doi.org/10.1109/20.950822
Publication status	Published - 2001 Jul
Externally published	Yes

Keywords

Co-Pt
Coercivity
Dipolar interaction
Fine particle
Magnetic anisotropy

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Access to Document

10.1109/20.950822

Cite this

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title = "Synthesis of Co100-xPtx alloy fine particles with high coercivity",

abstract = "In the present study, we have prepared and investigated Co100-xPtx (0 ≤ x ≤ 40) fine particles with the average diameter of D = 3 ∼ 40nm. At a fixed D ∼ 10 nm, the room temperature coercivity Hc increases with the Pt content x and takes a maximum value of 1000 Oe at x ∼ 25 at.% for 3D random assemblies of the particles. Such remarkable enhancement of the coercivity due to Pt is attributed to very strong magnetic anisotropy, as evaluated by the law of approach to saturation. At x ∼ 25 at.%, Hc increases with D due to suppression of thermal agitation and takes a maximum of 4000 Oe around at D ∼ 15 nm. Micromagnetic calculations taking into account dipolar interactions between particles have verified that the magnetic behaviours of Co75Pt25 fine particles can be explained by the coherent rotation model.",

keywords = "Co-Pt, Coercivity, Dipolar interaction, Fine particle, Magnetic anisotropy",

author = "Takahiro Ibusuki and Tomoaki Sakurai and Osamu Kitakami and Yutaka Shimada",

note = "Funding Information: Manuscript received October 16, 2000. This work is supported by the Research for The Future Program of Japan Society for the Promotion of Science under Grant 97R14701, and Storage Research Consortium in Japan. The authors are with the Research Institute for Scientific Measurements, To-hoku University, 980-8577 Sendai, Japan (e-mail: ibusuki@rism.tohoku.ac.jp). Publisher Item Identifier S 0018-9464(01)05624-2.",

year = "2001",

month = jul,

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language = "English",

volume = "37",

pages = "1295--1298",

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T1 - Synthesis of Co100-xPtx alloy fine particles with high coercivity

AU - Ibusuki, Takahiro

AU - Sakurai, Tomoaki

AU - Kitakami, Osamu

AU - Shimada, Yutaka

N1 - Funding Information: Manuscript received October 16, 2000. This work is supported by the Research for The Future Program of Japan Society for the Promotion of Science under Grant 97R14701, and Storage Research Consortium in Japan. The authors are with the Research Institute for Scientific Measurements, To-hoku University, 980-8577 Sendai, Japan (e-mail: ibusuki@rism.tohoku.ac.jp). Publisher Item Identifier S 0018-9464(01)05624-2.

PY - 2001/7

Y1 - 2001/7

N2 - In the present study, we have prepared and investigated Co100-xPtx (0 ≤ x ≤ 40) fine particles with the average diameter of D = 3 ∼ 40nm. At a fixed D ∼ 10 nm, the room temperature coercivity Hc increases with the Pt content x and takes a maximum value of 1000 Oe at x ∼ 25 at.% for 3D random assemblies of the particles. Such remarkable enhancement of the coercivity due to Pt is attributed to very strong magnetic anisotropy, as evaluated by the law of approach to saturation. At x ∼ 25 at.%, Hc increases with D due to suppression of thermal agitation and takes a maximum of 4000 Oe around at D ∼ 15 nm. Micromagnetic calculations taking into account dipolar interactions between particles have verified that the magnetic behaviours of Co75Pt25 fine particles can be explained by the coherent rotation model.

AB - In the present study, we have prepared and investigated Co100-xPtx (0 ≤ x ≤ 40) fine particles with the average diameter of D = 3 ∼ 40nm. At a fixed D ∼ 10 nm, the room temperature coercivity Hc increases with the Pt content x and takes a maximum value of 1000 Oe at x ∼ 25 at.% for 3D random assemblies of the particles. Such remarkable enhancement of the coercivity due to Pt is attributed to very strong magnetic anisotropy, as evaluated by the law of approach to saturation. At x ∼ 25 at.%, Hc increases with D due to suppression of thermal agitation and takes a maximum of 4000 Oe around at D ∼ 15 nm. Micromagnetic calculations taking into account dipolar interactions between particles have verified that the magnetic behaviours of Co75Pt25 fine particles can be explained by the coherent rotation model.

KW - Co-Pt

KW - Coercivity

KW - Dipolar interaction

KW - Fine particle

KW - Magnetic anisotropy

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