Growth and characterization of In1-xMnxAs diluted magnetic semiconductors quantum dots

被引:8
作者
Primus, JL
Choi, KH
Trampert, A
Yakunin, AM
Ferré, J
Wolter, JH
Van Roy, W
De Boeck, J
机构
[1] IMEC, B-3001 Louvain, Belgium
[2] Paul Drude Inst Festkorperelekt, D-10117 Berlin, Germany
[3] Eindhoven Univ Technol, Inter Univ Res Inst, COBRA, NL-5600 MB Eindhoven, Netherlands
[4] Univ Paris 11, CNRS, UMR 8502, Phys Solides Lab, F-91405 Orsay, France
关键词
nanostructures; molecular beam epitaxy; magnetic materials; semiconducting III-V materials;
D O I
10.1016/j.jcrysgro.2005.03.027
中图分类号
O7 [晶体学];
学科分类号
0702 ; 070205 ; 0703 ; 080501 ;
摘要
The growth of low-temperature In1-xMnxAs quantum dots (QD) on low-temperature GaAs(001) was investigated. Three different growth conditions with variable As-2 flux, Mn:In flux ratio and QD layer thickness were studied by atomic force microscopy and transmission electron microscopy. All three conditions generated In1-xMnxAs QD with a cubic crystal structure. It is shown that an excess of As-2 combined with a flux ratio of Mn:In = 0.10 and a limited deposited thickness of 5.4 ML In0.59Mn0.41As are the best conditions to obtain symmetric QD coherent to the substrate. Photoluminescence analysis performed on the latter samples showed a narrow band near 1100 nm, indicating 3D-confinement of the dots. The magnetic properties of a multilayer of 5.4ML In0.59Mn0.41As QD were analyzed by magneto-optical Kerr effect at 1.6K. No magnetization could be detected, whereas measurements performed on a multilayer of 2.4 ML In0.59Mn0.41As quantum wells indicated ferromagnetism. The absence of ferromagnetism for the QD is assigned to the superparamagnetism of the islands and the low Mn:In ratio used for the growth. It is suggested that these growth conditions are generating QD with a lower chance for interdot exchange interaction within a layer. (c) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:32 / 43
页数:12
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