Structural stability of (Ga,M) As from first principles : Random alloys, ordered compounds, and superlattices
ABSTRACT: We calculate by a combination of density functional theory and mixed-basis cluster expansion the structural stability of ordered and disordered zincblende GaAs-MnAs systems. We find that the ground state of this system is phase separating into GaAs+MnAs, even though the strain energy is ne...
- Autores:
-
Osorio Guillén, Jorge Mario
Zhao, Yu-Jun
Barabash, Sergey V.
Zunger, Alex
- Tipo de recurso:
- Article of investigation
- Fecha de publicación:
- 2006
- Institución:
- Universidad de Antioquia
- Repositorio:
- Repositorio UdeA
- Idioma:
- eng
- OAI Identifier:
- oai:bibliotecadigital.udea.edu.co:10495/8299
- Acceso en línea:
- http://hdl.handle.net/10495/8299
- Palabra clave:
- Aleaciones aleatorias
Compuestos ordenados
Densidad
Estabilidad estructural
Magnetismo
Semiconductores
- Rights
- openAccess
- License
- Atribución-NoComercial-SinDerivadas 2.5 Colombia
| Summary: | ABSTRACT: We calculate by a combination of density functional theory and mixed-basis cluster expansion the structural stability of ordered and disordered zincblende GaAs-MnAs systems. We find that the ground state of this system is phase separating into GaAs+MnAs, even though the strain energy is negligible. The study of short-period superlattices shows that the least-unstable superlattices are along the (111) orientation whereas the most-unstable orientation is the (201). The formation enthalpy of the random alloy has been calculated; combining it with a mean-field approximation, we obtain the temperature-composition phase diagram showing the miscibility-gap temperature below which the alloy phase separates (…). |
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