Self-organized Sr leads to solid state twinning in nano-scaled eutectic Si phase.
Sci Rep
; 6: 31635, 2016 08 16.
Article
en En
| MEDLINE
| ID: mdl-27527789
ABSTRACT
A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed. Observations made by sub-angstrom resolution scanning transmission electron microscopy and X-ray probing proved the presence of <110> Sr columns located preferentially at twin boundaries. Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the <110> direction, with preferential positions at first and second nearest neighbors for interstitial and substitutional Sr, respectively. Density functional theory total energy calculations confirm that twin nucleation at Sr columns is energetically favorable. Hence, twins may nucleate in Si precipitates after solidification, which provides a different perspective to the currently accepted mechanism which suggests twin formation during precipitate growth.
Texto completo:
1
Bases de datos:
MEDLINE
Idioma:
En
Revista:
Sci Rep
Año:
2016
Tipo del documento:
Article
País de afiliación:
Austria