| AVS 54th International Symposium | |
| Magnetic Interfaces and Nanostructures | Thursday Sessions |
| Session MI-ThA |
| Session: | Magnetic Semiconductors II |
| Presenter: | W. Zhu, University of Tennessee |
| Authors: | W. Zhu, University of Tennessee M. Yoon, University of Tennessee and ORNL Z. Zhang, ORNL and University of Tennessee |
| Correspondent: | Click to Email |
The spatial distribution of magnetic dopants in diluted magnetic semiconductors is critical in determining the magnetic property of the materials. Traditionally, the magnetic dopants were viewed to be homogeneously distributed in the host semiconductors. Recently, self-assembled Mn-rich nanocolumns were observed experimentally in (Ge,Mn) epitaxial films, which exhibit remarkable magnetic properties.1 Here, we propose a microscopic formation mechanism for the nanocolumns, involving the interplay between the electrostatic attractions of oppositely charged Mn ions and effective long-range repulsions due to elastic effect. Based on first-principles calculations and kinetic Monte Carlo simulations, we show that the proposed mechanism can successfully explain the formation of the self-assembled Mn-rich nanocolumns in the (Ge,Mn) epitaxial systems. We also discuss the potential applicability of the proposed model to other related systems.
*Work supported by US. NSF (Grant No. DMR-0606485), and by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with ORNL, managed and operated by UT-Battelle, LLC.
1 M. Jamet et al., Nat. Mater. 5, 653 (2006); A. P. Li et al., Phys. Rev. B 75, 201201(R) (2007).