Atomic and electronic structure of 〈110〉 symmetric tilt boundaries in palladium

In the present study, the energy and atomic structure of the 〈110〉 symmetric tilt boundaries in palladium were evaluated using the molecular dynamics (MD) simulation and the electronic structures of hydrogen in the bulk and on the grain boundaries of palladium were calculated using the discrete- variational Xα (DV-Xα) method. The MD simulation revealed that the energy of the 〈110〉 symmetric tilt boundary of palladium depended on the misorientation angle and that there were large energy cusps at the misorientation angles which corresponded to the (111) Σ3 and (113) Σ11 symmetric tilt boundaries. The atomic structure of all 〈110〉 symmetric tilt boundaries could consist of the combination of the (331) Σ19, (111) Σ3 and (113) Σ11 structural units and (110) Σ1 and (001) Σ1 single crystal units. The DV-Xα calculation showed that the interstitial hydrogen atoms in palladium induced the Pd-H chemical bond which had a different energy level than the Pd-Pd bond. The energy level and component of the Pd-H bonding on the grain boundaries in palladium were similar to those in the bulk palladium.