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Title: Cohesive Relations for Surface Atoms in the Iron-Technetium Binary System

Iron-technetium alloys are of relevance to the development of waste forms for disposition of radioactive technetium-99 obtained from spent nuclear fuel. Corrosion of candidate waste forms is a function of the local cohesive energy () of surface atoms. A theoretical model for calculating is developed. Density functional theory was used to construct a modified embedded atom (MEAM) potential for iron-technetium. Materials properties determined for the iron-technetium system were in good agreement with the literature. To explore the relationship between local structure and corrosion, MEAM simulations were performed on representative iron-technetium alloys and intermetallics. Technetium-rich phases have lower , suggesting that these phases will be more noble than iron-rich ones. Quantitative estimates of based on numbers of nearest neighbors alone can lead to errors up to 0.5 eV. Consequently, atomistic corrosion simulations for alloy systems should utilize physics-based models that consider not only neighbor counts, but also local compositions and atomic arrangements.
Authors:
 [1]
  1. Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87544, USA
Publication Date:
OSTI Identifier:
1198039
Grant/Contract Number:
AC52-06NA25396
Type:
Published Article
Journal Name:
Journal of Metallurgy
Additional Journal Information:
Journal Volume: 2011; Related Information: CHORUS Timestamp: 2016-08-04 13:46:58; Journal ID: ISSN 1687-9465
Publisher:
Hindawi Publishing Corporation
Sponsoring Org:
USDOE
Country of Publication:
Country unknown/Code not available
Language:
English