The elecronic structure and bonding of H pairs at S=5 BCC Fe grain boundary

S. B. GESARI; M. E. PRONSATO; A. JUAN

APPLIED SURFACE SCIENCE

Elsevier B. V

Año: 2002 vol. 187 p. 207 - 217

0169-4332

The H-Fe interaction at a grain boundary (GB)  in BCC Fe was studied using qualitative electronic structure calculations in the framework of the atom superposition and electron delocalization molecular orbital  (ASED-MO) theory. Calculations were performed using an Fe196 cluster to simulate the 36.9° [100]{013} symmetrical tilt GB structure. The most stable positions for one H atom and two H atoms at the GB core were determined. The total energy of the cluster decreases when the H atoms are at that location, making it a possible site for H accumulation. An analysis of the orbital interaction reveals that H-Fe bonding involves mainly the Fe 4s and H 1s orbitals. In general , H drain charge form the first neighbor Fe atoms.