Magnetic and microwave properties of cobalt nanoplatelets

被引：117

作者：

Li, Jiangong ^{[1
]}

Huang, Juanjuan ^{[1
]}

Qin, Yong ^{[1
]}

Ma, Fei ^{[1
]}

机构：

[1] Lanzhou Univ, Inst Mat Sci & Engn, Lanzhou 730000, Peoples R China

来源：

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY | 2007年 / 138卷 / 03期

基金：

中国国家自然科学基金;

关键词：

Co nanoplatelet; magnetic configuration; complex permeability; complex permittivity; microwave absorption;

D O I：

10.1016/j.mseb.2006.12.001

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The Co nanoplatelets of 120 nm in diameter and 10 nm in thickness exist in both fcc and hcp crystal structures at room temperature. The saturation magnetization of the Co nanoplatelets is lower than that of the bulk Co because of the existence of the oxide layer. The coercivity is higher than that of the bulk Co. The equilibrium magnetic configuration of a single Co nanoplatelet without external magnetic field is a vortex structure, regardless of hcp or fee crystal structure. The Co nanoplatelets were coated by MnO2. The microwave properties of the MnO2-coated Co nanoplatelet composites and paraffin wax mixtures were measured in the 0.1-18 GHz frequency range. The complex permeability of the sample shows two broad resonance peaks and the complex permittivity of the sample shows one resonance peak in the frequency range of 0.1-18 GHz. The numerical simulations show that the reflection loss values of the MnO2-coated Co nanoplatelet composites and paraffin wax mixtures are less than - 12 dB in the 2-11.5 GHz frequency range. (C) 2007 Elsevier B.V. All rights reserved.

引用

页码：199 / 204

页数：6

共 39 条

[11]

Hansen M., 1958, CONSTITUTION BINARY, DOI DOI 10.1149/1.2428700

[12] Boundary and finite-size effects in small magnetic systems [J].

Kachkachi, H ;

Garanin, DA .

PHYSICA A, 2001, 300 (3-4) :487-504

[13] Size effect on the crystal phase of cobalt fine particles [J].

Kitakami, O ;

Sato, H ;

Shimada, Y ;

Sato, F ;

Tanaka, M .

PHYSICAL REVIEW B, 1997, 56 (21) :13849-13854

[14] Structure and magnetic properties of cobalt nanoplatelets [J].

Li, JG ;

Qin, Y ;

Kou, XL ;

He, HY ;

Song, DK .

MATERIALS LETTERS, 2004, 58 (20) :2506-2509

[15]

LI JQ, UNPUB

[16] Particle features, oxidation behaviors and magnetic properties of ultrafine particles of Ni-Co alloy prepared by hydrogen plasma metal reaction [J].

Li, XG ;

Murai, T ;

Chiba, A ;

Takahashi, S .

JOURNAL OF APPLIED PHYSICS, 1999, 86 (04) :1867-1873

[17] Electromagnetic wave absorption properties of α-Fe/Fe3B/Y2O3 nanocomposites in gigahertz range [J].

Liu, JR ;

Itoh, M ;

Machida, K .

APPLIED PHYSICS LETTERS, 2003, 83 (19) :4017-4019

[18] A gigahertz-range electromagnetic wave absorber with wide bandwidth made of hexagonal ferrite [J].

Matsumoto, M ;

Miyata, Y .

JOURNAL OF APPLIED PHYSICS, 1996, 79 (08) :5486-5488

[19] Thin electromagnetic wave absorber for quasi-microwave band containing aligned thin magnetic metal particles [J].

Matsumoto, M ;

Miyata, Y .

IEEE TRANSACTIONS ON MAGNETICS, 1997, 33 (06) :4459-4464

[20] Magnetic resonance in spherical Co-Ni and Fe-Co-Ni particles [J].

Mercier, D ;

Lévy, JCS ;

Viau, G ;

Fiévet-Vincent, F ;

Fiévet, F ;

Toneguzzo, P ;

Acher, O .

PHYSICAL REVIEW B, 2000, 62 (01) :532-544

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