The release behavior of helium in palladium nanowire: A molecular dynamics study

Molecular dynamics (MD) simulation is employed to investigate the release behavior of helium and its effect on the mechanical properties of palladium (Pd) nanowire. The results indicate that the helium atom can assemble easily to form a helium bubble, which effectively degrade the mechanical properties of Pd nanowire as the bubble size increases. Then, the development propensities of the helium bubble pressure is discussed with the helium atoms continuously releasing, which shows that the relationship between the pressure and the volume of the helium bubble is in well agreement with the description of the state equation. On the basis, it is further found that the release rate of helium has a tight connection with the variation of the bubble pressure in nanowire. Finally, the inherent mechanism of helium releasing from the Pd nanowire is analyzed in detail. (C) 2015 Elsevier B.V. All rights reserved.