First-principles calculation of H vibrational excitations at a dislocation core of Pd

Abstract

Palladium is an ideal system for understanding the behavior of hydrogen in metals. In Pd, H is located both in octahedral sites and in dislocation cores, which act as nanoscale H traps and form Cottrell atmospheres. Adjacent to a dislocation core, H experiences the largest possible distortion in alpha-Pd. Ab initio density-functional theory computes the potential energy for a hydrogen in an octahedral site in alpha-Pd and in a trap site at the core of a partial of an edge dislocation. The Pd partial dislocation core changes the environment for H, distorting the H-Pd bonding which changes the local potential, vibrational spectra, and inelastic form factor for an isolated H atom. The decrease in excitation energy is consistent with experiments, and the calculations predict distortions to the H wavefunction.

12 pages, 3 figures

References in corpus (2)

• Conductance of Pd-H nanojunctions
• Lattice Green function for extended defect calculations: Computation and error estimation with long-range forces

Cited by in corpus (1)

• Nanoscale-hydride formation at dislocations in palladium: Ab initio theory and incoherent inelastic neutron scattering measurements