Enhanced H-H binding and consequent H-aggregation around dislocation in α-Fe lattice

Abstract

H-H binding energies in tetragonal and octahedral sites (TS & OS) of α -Fe lattice were calculated by density functional theory (DFT) under correction of elastic energy. Strong attractive interactions were identified as H atoms were incorporated in 3rd and 4th nearest OS neighbors. OS-type H-aggregated clusters with binding energies exceeding 200 meV were identified. Monte Carlo simulation of H-loading indicates abnormal H-aggregation behavior around a 1/2[111] $(10\bar{1})$ edge dislocation in relation with the enhanced H-H binding specifically in OS of α -Fe lattice.

Keywords

• DFT
• H-H binding energy
• Monte Carlo simulation
• H-clusters