Overcoming the dipolar disorder in dense CoFe nanoparticle ensembles:: Superferromagnetism

被引：140
作者：
Bedanta, S.
Eimueller, T.
Kleemann, W. [1 ]
Rhensius, J.
Stromberg, F.
Amaladass, E.
Cardoso, S.
Freitas, P. P.
机构：
[1] Univ Duisburg Essen, D-47048 Duisburg, Germany
[2] Ruhr Univ Bochum, D-44780 Bochum, Germany
[3] Max Planck Inst Met Res, D-70569 Stuttgart, Germany
[4] INESC, P-1000 Lisbon, Portugal
来源：
PHYSICAL REVIEW LETTERS | 2007年 / 98卷 / 17期
关键词：
D O I：
10.1103/PhysRevLett.98.176601
中图分类号：
O4 [物理学];
学科分类号：
0702 ;
摘要：
In a dense ensemble of physically nonpercolating FM nanoparticles embedded in a [Co80Fe20/Al2O3](10) multilayer the long-discussed superferromagnetic (SFM) state has been evidenced by imaging homogeneously magnetized SFM domain patterns with x-ray photoemission electron microscopy and magneto-optical Kerr microscopy. Competing dipolar and exchange interactions give rise to extremely rough domain walls similarly as in hard multigrain magnets. The SFM state is characterized by extreme magnetic softness and higher order tunneling conductivity due to atomically small intercalated particles promoting the SFM order.
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页数：4
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