Magnetic anisotropy and its temperature dependence in iron-rich FexPt1-x nanoparticles

被引：64

作者：

Antoniak, C ^{[1
]}

Lindner, J ^{[1
]}

Farle, M ^{[1
]}

机构：

[1] Univ Duisburg Essen, Fachbereich Phys, D-47048 Duisburg, Germany

来源：

EUROPHYSICS LETTERS | 2005年 / 70卷 / 02期

关键词：

D O I：

10.1209/epl/i2004-10485-9

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The effective magnetic anisotropy K(ef)f of chemically disordered Fe70Pt30 particles with a mean diameter of 2.3 nm is shown to be temperature dependent between 50 K and 350 K. From the determination of the blocking temperatures by field-cooled and zero-field-cooled magnetisation measurements and ferromagnetic resonance experiments, that is in two different time windows, we find K-eff = (8.4 +/- 0.9) x 10(5) J/m(3) at 23 K. This is found to be one order of magnitude larger than the bulk material value for the disordered phase. This value is confirmed by quantitative simulations of the experimentally determined zero-field-cooled magnetisation and can be explained by the large contribution of surface anisotropy, small deviations from a spherical shape and the presence of an approximately one monolayer thick iron oxide shell.

引用

页码：250 / 256

页数：7

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