First-principles calculation of sulfur–selenium segregation in ZnSe1−xSx: The role of lattice vibration
| Autor: | Hong-Tao Xue, Wen-Jiang Lu, Xiao Kang Li, Fu-Ling Tang |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Condensed matter physics Basis (linear algebra) Spinodal decomposition Mechanical Engineering Monte Carlo method chemistry.chemical_element Condensed Matter Physics Sulfur chemistry Mechanics of Materials General Materials Science Density functional theory Selenium Cluster expansion Phase diagram |
| Zdroj: | Materials Science in Semiconductor Processing. 39:96-102 |
| ISSN: | 1369-8001 |
| DOI: | 10.1016/j.mssp.2015.03.024 |
| Popis: | First-principles phase diagram calculations based on density functional theory within the generalized gradient approximation in combination with Monte Carlo (MC) techniques and cluster expansion were performed for the ZnSe1−xSx alloys. Formation energies were used as a basis for fitting cluster expansion Hamiltonians. All formation energies of ZnSe1−xSx alloys are positive, showing that ZnSe1−xSx alloys is a miscibility gap system and has a tendency to phase separation. For ZnSe1−xSx alloys the phase diagram computed with conventional cluster expansion shows a miscibility gap with consolute temperature Tc=327 K. The contributions of lattice vibration reduce Tc to 281 K (about 15%). We presented a MC study of the spatial distribution of S and Se in ZnSe0.5S0.5 alloys. We found that, the system becomes more homogeneous including lattice vibration at lower temperature. It is consistence with the calculation of phase diagram of ZnSe1−xSx alloys. |
| Databáze: | OpenAIRE |
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