The structure of small Ta clusters
Abstract
The structure of small tantalum clusters is investigated by using molecular dynamics simulations. A structural evolution from polytetrahedral structures to layered Frank-Kasper-type structures is revealed as cluster size increases to N~100 atoms. The lowest-energy structures have been located for clusters with N<=78. The bulk-like (bcc) structure becomes the most stable structure beyond N~100. The stabilized structure strongly depends on the cooling rate. A structure similar to β-Ta, a σ-type Frank-Kasper structure, can be obtained by rapid cooling. The structural properties of small Ta clusters presented in the paper provide insight into the formation and origin of β-phase Ta. The growth of β-Ta films in practice may be due to the nucleation of Ta clusters with layered Frank-Kasper-type structure during the initial stage of film growth.
- Publication:
-
Journal of Physics Condensed Matter
- Pub Date:
- October 2005
- DOI:
- 10.1088/0953-8984/17/39/001
- Bibcode:
- 2005JPCM...17.6111J