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arXiv · 1008.1256

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

Hadley M. Lawler·Dallas R. Trinkle
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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.

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Hadley M. Lawler, Dallas R. Trinkle. 2010-08-06. First-principles calculation of H vibrational excitations at a dislocation core of Pd. https://doi.org/10.1103/physrevb.82.172101

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