Clustering in a precipitate-free GeMn magnetic semiconductor

被引：116

作者：

Bougeard, D.

Ahlers, S.

Trampert, A.

Sircar, N.

Abstreiter, G.

机构：

[1] Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany

[2] Paul Drude Inst Festkorperelekt, D-10117 Berlin, Germany

来源：

PHYSICAL REVIEW LETTERS | 2006年 / 97卷 / 23期

关键词：

D O I：

10.1103/PhysRevLett.97.237202

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present the first study relating structural parameters of precipitate-free Ge0.95Mn0.05 films to magnetization data. Nanometer-sized clusters-areas with increased Mn content on substitutional lattice sites compared to the host matrix-are detected in transmission electron microscopy analysis. The films show no overall spontaneous magnetization at all down to 2 K. The TEM and magnetization results are interpreted in terms of an assembly of superparamagnetic moments developing in the dense distribution of clusters. Each cluster individually turns ferromagnetic below an ordering temperature which depends on its volume and Mn content.

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页数：4

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