Title:
First-principles calculations of helium cluster formation in palladium tritides

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dc.contributor.advisor Chou, Mei-Yin
dc.contributor.author Lin, Pei en_US
dc.contributor.committeeMember First, Phillip N.
dc.contributor.committeeMember Gole, James
dc.contributor.committeeMember Sholl, David
dc.contributor.committeeMember Zangwill, Andrew
dc.contributor.department Physics en_US
dc.date.accessioned 2011-09-22T17:48:12Z
dc.date.available 2011-09-22T17:48:12Z
dc.date.issued 2010-05-20 en_US
dc.description.abstract The accumulation of helium atoms in metals or metal tritides is known to result in the formation of helium bubbles in the lattice and to cause degradation of the material. Helium is introduced either through neutron transmutation reaction or via the radioactive decay of tritium. We have performed first-principles calculations of interstitial helium inside Pd and Pd tritide using density functional theory (DFT) and the projector augmented-wave (PAW) method within the generalized gradient approximation (GGA). We model the growth process of an interstitial helium cluster and find that when the size of the cluster reaches to five atoms, the cluster can induce an energetically favorable vacancy with a self-trapping mechanism. The cluster growth mechanism of interstitial helium is addressed by investigating the associated energetics, cluster configurations, and electronic structural properties. In addition, we study the diffusion properties of helium in palladium-based compounds by performing the nudged elastic band (NEB) calculations. Our computational models propose that by loading the lattice with hydrogen atoms at certain concentration, or substituting with alloying metals can modify the diffusivity by increasing its migration barrier, which may impede the cluster formation in the beginning stage. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/41103
dc.publisher Georgia Institute of Technology en_US
dc.subject Palladium tritides en_US
dc.subject Helium bubbles en_US
dc.subject First-principles en_US
dc.subject.lcsh Metals Helium content
dc.subject.lcsh Palladium
dc.subject.lcsh Tritium
dc.title First-principles calculations of helium cluster formation in palladium tritides en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Physics
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication 2ba39017-11f1-40f4-9bc5-66f17b8f1539
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