This title appears in the Scientific Report :
2012
Please use the identifier:
http://hdl.handle.net/2128/4963 in citations.
Please use the identifier: http://dx.doi.org/10.1103/PhysRevB.84.245306 in citations.
Formation process and superparamagnetic proberties of (Mn,Ga)As nanocrystals in GaAs fabricated by annealing of (Ga,Mn)As layers with low Mn content
Formation process and superparamagnetic proberties of (Mn,Ga)As nanocrystals in GaAs fabricated by annealing of (Ga,Mn)As layers with low Mn content
X-ray diffraction, transmission electron microscopy, and magnetization measurements are employed to study the structural and magnetic properties of Mn-rich (Mn,Ga)As nanocrystals embedded in GaAs. These nanocomposites are obtained by moderate (400C) and high temperature (560 and 630C) annealing of (...
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Personal Name(s): | Sadowski,J. (Corresponding author) |
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Domagala,J. / Mathieu,R. / Kovacs, Andras / Kasama,T. / Dunin-Borkowski, Rafal / Dietl,T. | |
Contributing Institute: |
Mikrostrukturforschung; PGI-5 |
Published in: | Physical Review B Physical review / B, 84 84 (2011 2011) 24 24, S. 245306 245306 |
Imprint: |
College Park, Md.
APS
2011
|
DOI: |
10.1103/PhysRevB.84.245306 |
Document Type: |
Journal Article |
Research Program: |
Peter Grünberg-Centre (PG-C) |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1103/PhysRevB.84.245306 in citations.
X-ray diffraction, transmission electron microscopy, and magnetization measurements are employed to study the structural and magnetic properties of Mn-rich (Mn,Ga)As nanocrystals embedded in GaAs. These nanocomposites are obtained by moderate (400C) and high temperature (560 and 630C) annealing of (Ga,Mn)As layers with Mn concentrations between 0.1 and 2%, grown by molecular beam epitaxy at 270oC. Decomposition of (Ga,Mn)As is already observed at the lowest annealing temperature of 400C for layers with initial Mn content of 1% and 2%. Both cubic and hexagonal (Mn,Ga)As nanocrystals, with similar diameters of 7 - 10 nm are observed to coexist in layers with an initial Mn content of 0.5% after higher temperature annealing. Measurements of magnetization relaxation in the time span 0.1 - 10 000 s provide evidence for superparamagnetic properties of the (Mn,Ga)As nanocrystals, as well as for the absence of spin-glass dynamics. These findings point to weak coupling between nanocrystals even in layers with the highest nanocrystal density. |