Abstract
The magnetic properties of the ferromagnetic semiconductor In0.98 Mn0.02 As were characterized by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. The Mn exhibits an atomic-like L2,3 absorption spectrum that indicates that the 3d states are highly localized. In addition, a large dichroism at the Mn L2,3 edge was observed from 5 to 300 K at an applied field of 2T. A calculated spectrum assuming atomic Mn2+ yields the best agreement with the experimental InMnAs spectrum. A comparison of the dichroism spectra of MnAs and InMnAs shows clear differences suggesting that the ferromagnetism observed in InMnAs is not due to hexagonal MnAs clusters. The temperature dependence of the dichroism indicates the presence of two ferromagnetic species, one with a transition temperature of 30 K and another with a transition temperature in excess of 300 K. The dichroism spectra are consistent with the assignment of the low temperature species to random substitutional Mn and the high temperature species to Mn near-neighbor pairs.
Original language | English (US) |
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Article number | 072505 |
Pages (from-to) | 1-3 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 86 |
Issue number | 7 |
DOIs | |
State | Published - Feb 14 2005 |
Funding
The authors would like to thank J. H. Song of Northwestern University for providing the sample and Professor M. van Veenendaal of Northern Illinois University for providing the atomic multiplet code and for helpful discussions. This work is supported by the NSF under the Spin Electronics Program #ECS-0224210 and the MRSEC program under Contract No. DMR-0076797. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, under Contract No. W-31-109-Eng-38.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)