Effect of Hydrogen on the Electronic Structure of a Grain Boundary in Iron
Abstract
Linear Muffin-Tin Orbitals-Atomic Sphere Approximation (LMTO-ASA) calculations were performed on a 26-atom supercell model of a (111) grain boundary (GB) in bcc Fe. The supercell emulated two GBs with 11 (111) planes of Fe atoms between the GB planes. One of the GBs was clean, with a structural vacancy at the GB core in the center of a trigonal prism of Fe atoms, while on other GB site was occupied by an H atom. The interplanar spacings of the supercell were relaxed using a modified embedded atom method. As in the case of P and S in a similar GB environment in Fe, there is only a weak interaction between H and the nearest Fe atoms. Almost all the Fe d-states are nonbonding. A very weak covalent bond exists between H and Fe due to s-pd hybridization; the hybrid bonding band located far below the Fermi energy (Ef). this bond is mostly of sigma-type, connecting H with Fe atoms in the GB plane; the delta-component of this bond across the GB is weaker.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1991
- Accession Number
- ADA237499
Entities
People
- Genrich L. Krasko
- Gregory B. Olson