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Title: Point defect structures of YA1 2 and ZrCo 2 Laves phase compounds by first-principles calculations

Abstract

In Laves phase alloys with prominent size mismatch between constituent atoms and/or large negative enthalpy of formation, the existence of vacancies as the dominant point defect type is often suggested. However, there are not enough experimental data to prove or disprove these arguments. Employing first-principles calculations, we study the point defect structures of YAl{sub 2} and ZrCo{sub 2} C15 Laves phases, as both compounds exhibit large size mismatch between constituent atoms, and large negative enthalpy of formation. We find that one must go beyond the simple geometrical or enthalpy arguments in determining the point defect structures of these alloys. In both compounds, the point defect structure is found to be dominated by the anti-site defects on the larger atom-rich side of the stoichiometry.

Authors:
 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
931630
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Intermetallics; Journal Volume: 15; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; YTTRIUM ALLOYS; ALUMINIUM ALLOYS; ZIRCONIUM ALLOYS; COBALT ALLOYS; ENTHALPY; FORMATION HEAT; LAVES PHASES; POINT DEFECTS

Citation Formats

Krcmar, Maja, and Fu, Chong Long. Point defect structures of YA12 and ZrCo2 Laves phase compounds by first-principles calculations. United States: N. p., 2007. Web. doi:10.1016/j.intermet.2006.02.004.
Krcmar, Maja, & Fu, Chong Long. Point defect structures of YA12 and ZrCo2 Laves phase compounds by first-principles calculations. United States. doi:10.1016/j.intermet.2006.02.004.
Krcmar, Maja, and Fu, Chong Long. Mon . "Point defect structures of YA12 and ZrCo2 Laves phase compounds by first-principles calculations". United States. doi:10.1016/j.intermet.2006.02.004.
@article{osti_931630,
title = {Point defect structures of YA12 and ZrCo2 Laves phase compounds by first-principles calculations},
author = {Krcmar, Maja and Fu, Chong Long},
abstractNote = {In Laves phase alloys with prominent size mismatch between constituent atoms and/or large negative enthalpy of formation, the existence of vacancies as the dominant point defect type is often suggested. However, there are not enough experimental data to prove or disprove these arguments. Employing first-principles calculations, we study the point defect structures of YAl{sub 2} and ZrCo{sub 2} C15 Laves phases, as both compounds exhibit large size mismatch between constituent atoms, and large negative enthalpy of formation. We find that one must go beyond the simple geometrical or enthalpy arguments in determining the point defect structures of these alloys. In both compounds, the point defect structure is found to be dominated by the anti-site defects on the larger atom-rich side of the stoichiometry.},
doi = {10.1016/j.intermet.2006.02.004},
journal = {Intermetallics},
number = 1,
volume = 15,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}