Antiferromagnetic spin ordering in the dissociative adsorption of H-2 on Si(001): Density-functional calculations

作者：Choi Jin Ho; Kim Kwang S; Cho Jun Hyung^*

来源：Journal of Chemical Physics, 2009, 131(24): 244704.

DOI：10.1063/1.3276916

• adsorption
• antiferromagnetic materials
• buckling
• dangling bonds
• density functional theory
• dissociation
• electronic density of states
• elemental semiconductors
• ground states
• hydrogen
• silicon

The dissociative adsorption of an H-2 molecule on the Si(001) surface, which has been experimentally identified in terms of dissociation on one side of two adjacent Si dimers, is investigated by spin polarized density-functional calculations within the generalized-gradient approximation. In contrast to the prevailing nonmagnetic configuration of charge ordering, we propose a new ground state where the two single dangling bonds (DBs) created by H-2 dissociation are antiferromagnetically coupled with each other. Such a spin ordering is found to be energetically favored over the previously proposed charge ordering. In the latter configuration, the buckling of the two DBs amounts to a height difference (Delta h) of 0.63 A degrees, caused by a Jahn-Teller-like distortion, while in the former configuration, their buckling is almost suppressed to be Delta h=0.03 A degrees as a consequence of spin polarization.

• 出版日期2009-12-28