Monte-Carlo Simulation of Hydrogen Motion in Nb-V-H alloys.
Abstract
Studies of hydrogen motion in random Nb-V-H alloys by NMR and internal friction indicate that: the motion is governed by a range of activation energies and (2) the dwell time of a hydrogen atom at low temperatures is much less than that calculated from the mean activation energy. On the other hand, bulk diffusion measurements and calculations from pressure vs. composition data suggest diffusion is determined by a single activation energy with accompanying large dwell times at low temperatures. To reconcile these results we have performed a Monte-Carlo simulation of hydrogen motion in these alloys and have adjusted parameters of the motion to produce results consistent with the experimental data. The NMR and internal friction data result from rapid local motion of the hydrogen, which does not influence the diffusion measurements. Our results will be compared with rapid local hydrogen motion found in neutron-scattering and molecular-dynamics studies of hydrogen in pure niobium.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1996
- Bibcode:
- 1996APS..MAR.S2307L