Study of the initial stages of Mn growth on Ge(001) substrates

Sion Olive-Mendez 1Lisa Michez 1Alain Ranguis 1Vinh Le Thanh 1François A. Davitaya 1Jacques Derrien 1Thibaut Devillers 2Matthieu Jamet 2Andre Barski 2

1. Centre de Recherche en Matière Condensée et Nanosciences (CRMCN-CNRS), Campus de Luminy, case 913, Marseille 13288, France
2. CEA Grenoble, Département de Recherche Fondamentale sur la Matière Condensée/SP2M, Grenoble 38054, France


In recent years, there has been a growing interest in synthesizing diluted magnetic semiconductrs (DMS), obtained by substituting 3d transition metal ions into nonmagnetic semiconductors. Among the various systems, which have been largely studied such as (Ga,Mn)As or II-VI DMS, Mn-doped Ge is of particular interest since it offers a direct route for integrating magnetism with existing silicon technology [1]. A result of particular interest is the recent observation of a new high-temperature ferromagnetic phase, consisting of nano-columns of ~4 nm in diameter and 10 nm in spacing [2]. To complete this work, we have combined STM with TEM to investigate the initial stages of Mn deposition on Ge(001) surfaces. The Ge deposition was carried out at two substrate temperatures: at 80 °C, a temperature which is usually used for growing MnGe DMS, and at 250 °C, temperature at which intermetallic precipitates have tendency to be formed. For Mn deposition at 80 °C, two distinct kinds of Mn islands are observed even for Mn coverage smaller than a monolayer. Big islands have an average size of ~4 nm and small islands have size of 1-2 nm. When the Mn coverage increases, coarsening between small islands with newly deposited adatoms occurs, giving rise to the formation of mono-sized islands. Interestingly, these islands have an average size of 4 nm and are separated by a spacing of 10 nm. High-resolution TEM analyses indicate that those islands are epitaxial, defect free and perfectly coherent with the Ge substrate. For a Mn deposition carried out at 250 °C, only one kind of islands is observed and they appear to be pinned at the surface steps. Nanoscale chemical analysis of the island composition by means of energy dispersive X-ray spectrometry and magnetic characterizations of samples are now in process.

[1] Y.D. Park et al., Science 295 (2002) 651;

[2] M. Jamet et al., French patent n° 06/01149 (2006); Accepted in Nature Materials 2006.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: must be provided.


Related papers
  1. On the formation of magnetic nanocomposites and impurity complexes in GaN doped with Fe and Mn
  2. High Curie temperature ferromagnetism in self-organized Ge1‑xMnx nano-columns
  3. Selective epitaxial growth of Ge/Si quantum dots on patterned Si(001) substrate by ultra high vacuum chemical vapor deposition

Presentation: Oral at E-MRS Fall Meeting 2006, Symposium E, by Sion Olive-Mendez
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-15 17:01
Revised:   2009-06-07 00:44
© 1998-2022 pielaszek research, all rights reserved Powered by the Conference Engine