Development of an interatomic potential for the simulation of phase transformations in zirconium

TitleDevelopment of an interatomic potential for the simulation of phase transformations in zirconium
Publication TypeJournal Article
Year of Publication2007
AuthorsMendelev MI, Ackland GJ
Journal TitlePhilosophical Magazine Letters
Type of ArticleArticle
ISBN Number0950-0839
Accession NumberISI:000246264400005
Keywordsalloys, ALPHA-ZR, aluminum, CLOSE-PACKED METALS, DEFECT PROPERTIES, diffusion, model, molecular-dynamics, point

In recent years, some 30 studies have been published on the molecular dynamics ( MD) of zirconium, primarily of its twinning deformation and response to radiation damage. Its low thermal neutron absorption makes it uniquely suited for the latter application. Surprisingly, currently used interatomic potentials do not encapsulate the unique properties of Zr, namely its high stacking-fault energy, anomolous self-diffusion, melting and phase transformation under temperature and pressure ( or alloying). Ab initio calculations have shown deficiencies in the description of point defects, both vacancies and interstitials, using existing interatomic potentials, deficiencies that can now be rectified by refitting. Here, we show the calculation of phase transitions self-consistently and present a potential for Zr that correctly reproduces the energetics of our extended database of ab initio configurations and high-temperature phase transitions. The potential has an analytic many-body form, making it suitable for existing large-scale MD codes. We also present a best-fit potential for the hcp structure and its defects.

Alternate JournalPhilos. Mag. Lett.