Formation process and superparamagnetic properties of (Mn,Ga)As nanocrystals in GaAs fabricated by annealing of (Ga,Mn)As layers with low Mn content
(2011) In Physical Review B (Condensed Matter and Materials Physics) 84(24). p.1-245306- Abstract
- 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 (400 C) and high temperature (560 and 630 C) 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 400 C 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... (More)
- 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 (400 C) and high temperature (560 and 630 C) 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 400 C 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. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2269435
- author
- Sadowski, Janusz LU ; Domagala, Jaroslaw ; Mathieu, Roland ; Kovacs, Andras ; Kasama, Takeshi ; Dunin-Borkowski, Rafal and Dietl, Tomasz
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- molecular beam epitaxy, nanomagnetism, magnetic semiconductors
- in
- Physical Review B (Condensed Matter and Materials Physics)
- volume
- 84
- issue
- 24
- pages
- 1 - 245306
- publisher
- American Physical Society
- external identifiers
-
- wos:000297934500005
- scopus:84855427401
- ISSN
- 1098-0121
- DOI
- 10.1103/PhysRevB.84.245306
- language
- English
- LU publication?
- yes
- id
- fa7c0347-1841-42f9-b19e-4a5ede8fa2c7 (old id 2269435)
- date added to LUP
- 2016-04-01 14:50:08
- date last changed
- 2022-04-14 19:56:44
@article{fa7c0347-1841-42f9-b19e-4a5ede8fa2c7,
abstract = {{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 (400 C) and high temperature (560 and 630 C) 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 400 C 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.}},
author = {{Sadowski, Janusz and Domagala, Jaroslaw and Mathieu, Roland and Kovacs, Andras and Kasama, Takeshi and Dunin-Borkowski, Rafal and Dietl, Tomasz}},
issn = {{1098-0121}},
keywords = {{molecular beam epitaxy; nanomagnetism; magnetic semiconductors}},
language = {{eng}},
number = {{24}},
pages = {{1--245306}},
publisher = {{American Physical Society}},
series = {{Physical Review B (Condensed Matter and Materials Physics)}},
title = {{Formation process and superparamagnetic properties of (Mn,Ga)As nanocrystals in GaAs fabricated by annealing of (Ga,Mn)As layers with low Mn content}},
url = {{http://dx.doi.org/10.1103/PhysRevB.84.245306}},
doi = {{10.1103/PhysRevB.84.245306}},
volume = {{84}},
year = {{2011}},
}