title: Impact of Mn on the solution enthalpy of hydrogen in austenitic Fe-Mn alloys: a first-principles study.
abstract: Hydrogen interstitials in austenitic Fe-Mn alloys were studied using density-functional theory to gain insights into the mechanisms of hydrogen embrittlement in high-strength Mn steels. The investigations reveal that H atoms at octahedral interstitial sites prefer a local environment containing Mn atoms rather than Fe atoms. This phenomenon is closely examined combining total energy calculations and crystal orbital Hamilton population analysis. Contributions from various electronic phenomena such as elastic, chemical, and magnetic effects are characterized. The primary reason for the environmental preference is a volumetric effect, which causes a linear dependence on the number of nearest-neighbour Mn atoms. A secondary electronic/magnetic effect explains the deviations from this linearity.
authors.affiliation: Institute of Inorganic Chemistry, RWTH Aachen University, D-52056, Aachen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: von Appen
authors.forename: Richard
authors.initials: R
authors.lastname: Dronskowski
authors.forename: Aurab
authors.initials: A
authors.lastname: Chakrabarty
authors.forename: Tilmann
authors.initials: T
authors.lastname: Hickel
authors.forename: Robert
authors.initials: R
authors.lastname: Spatschek
authors.forename: Jörg
authors.initials: J
authors.lastname: Neugebauer
keywords: austenitic steel; bonding analysis; hydrogen embrittlement; interaction energies; solution enthalpy