INVESTIGADORES
PRONSATO Maria Estela
artículos
Título:
EFFECTS OF SULFUR AND CARBON
ON THE ELECTRONIC STRUCTURE AND
EFFECTS OF SULFUR AND CARBON ON THE ELECTRONIC STRUCTURE AND BONDING OF A GRAIN BOUNDARY IN a -IRON
Autor/es:
S. B. GESARI; M. E. PRONSATO; A. JUAN
Revista:
SURFACE REVIEW AND LETTERS
Editorial:
World Scientific Publishing Company
Referencias:
Año: 2004 vol. 11 p. 145 - 153
ISSN:
0218-625X
Resumen:
The electronic structure of a grain boundary (GB) in a-Fe with segregated S and C impurity atoms was calculated by the atom superposition and electron delocalization molecular orbital (ASED-MO) theory. An Fe176 cluster model was used to simulate the local environment of the S=5 (013), 36.9º [100] tilt boundary.The results show a site competition on the GB between S and C. The C drives the S away from the boundaries. The C segregation is 4.77 eV more favorable than the S segregation.Both interstitials weaken Fe-Fe bonds perpendicular to the GB plane and simultaneously form new interstitial a-Fe bonds, although C presents the possibility of connecting the two halves of the crystal with a bridge Fe-C-Fe bond. These results should be important for understanding the complex mechanism for decohesion a-Fe.
