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Effect of low-temperature annealing on the electronic- and band-structures of (Ga,Mn) As epitaxial layers

Yastrubchak, O.; Wosinski, T.; Gluba, L.; Andrearczyk, T.; Domagala, J. Z.; Zuk, J. and Sadowski, Janusz LU (2014) In Applied Physics Reviews 115(1).
Abstract
The effect of outdiffusion of Mn interstitials from (Ga,Mn) As epitaxial layers, caused by post-growth low-temperature annealing, on their electronic- and band-structure properties has been investigated by modulation photoreflectance (PR) spectroscopy. The annealing-induced changes in structural and magnetic properties of the layers were examined with high-resolution X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. They confirmed an outdiffusion of Mn interstitials from the layers and an enhancement in their hole concentration, which were more efficient for the layer covered with a Sb cap acting as a sink for diffusing Mn interstitials. The PR results demonstrating a decrease in the... (More)
The effect of outdiffusion of Mn interstitials from (Ga,Mn) As epitaxial layers, caused by post-growth low-temperature annealing, on their electronic- and band-structure properties has been investigated by modulation photoreflectance (PR) spectroscopy. The annealing-induced changes in structural and magnetic properties of the layers were examined with high-resolution X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. They confirmed an outdiffusion of Mn interstitials from the layers and an enhancement in their hole concentration, which were more efficient for the layer covered with a Sb cap acting as a sink for diffusing Mn interstitials. The PR results demonstrating a decrease in the band-gap-transition energy in the as-grown (Ga,Mn) As layers, with respect to that in the reference GaAs one, are interpreted by assuming a merging of the Mn-related impurity band with the GaAs valence band. Whereas an increase in the band-gap-transition energy caused by the annealing treatment of the (Ga,Mn) As layers is interpreted as a result of annealing-induced enhancement of the free-hole concentration and the Fermi level location within the valence band. The experimental results are consistent with the valence-band origin of itinerant holes mediating ferromagnetic ordering in (Ga,Mn) As, in agreement with the Zener model for ferromagnetic semiconductors. (C) 2014 AIP Publishing LLC. (Less)
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type
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publication status
published
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in
Applied Physics Reviews
volume
115
issue
1
publisher
American Institute of Physics
external identifiers
  • wos:000329456300009
  • scopus:84892189589
ISSN
0021-8979
DOI
10.1063/1.4838036
language
English
LU publication?
yes
id
c775dc6c-69be-4ea3-a9f4-ae31b1e6636b (old id 4319590)
date added to LUP
2014-02-26 13:50:04
date last changed
2017-11-12 03:14:05
@article{c775dc6c-69be-4ea3-a9f4-ae31b1e6636b,
  abstract     = {The effect of outdiffusion of Mn interstitials from (Ga,Mn) As epitaxial layers, caused by post-growth low-temperature annealing, on their electronic- and band-structure properties has been investigated by modulation photoreflectance (PR) spectroscopy. The annealing-induced changes in structural and magnetic properties of the layers were examined with high-resolution X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. They confirmed an outdiffusion of Mn interstitials from the layers and an enhancement in their hole concentration, which were more efficient for the layer covered with a Sb cap acting as a sink for diffusing Mn interstitials. The PR results demonstrating a decrease in the band-gap-transition energy in the as-grown (Ga,Mn) As layers, with respect to that in the reference GaAs one, are interpreted by assuming a merging of the Mn-related impurity band with the GaAs valence band. Whereas an increase in the band-gap-transition energy caused by the annealing treatment of the (Ga,Mn) As layers is interpreted as a result of annealing-induced enhancement of the free-hole concentration and the Fermi level location within the valence band. The experimental results are consistent with the valence-band origin of itinerant holes mediating ferromagnetic ordering in (Ga,Mn) As, in agreement with the Zener model for ferromagnetic semiconductors. (C) 2014 AIP Publishing LLC.},
  articleno    = {012009},
  author       = {Yastrubchak, O. and Wosinski, T. and Gluba, L. and Andrearczyk, T. and Domagala, J. Z. and Zuk, J. and Sadowski, Janusz},
  issn         = {0021-8979},
  language     = {eng},
  number       = {1},
  publisher    = {American Institute of Physics},
  series       = {Applied Physics Reviews},
  title        = {Effect of low-temperature annealing on the electronic- and band-structures of (Ga,Mn) As epitaxial layers},
  url          = {http://dx.doi.org/10.1063/1.4838036},
  volume       = {115},
  year         = {2014},
}