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Point Defects in NiAl Alloys Under Pressure

  • Alexander Y. Lozovoi
  • Ali Alavi
  • Pavel A. Korzhavyi
  • Michael W. Finnis

Abstract

We investigate the effect of elevated pressures on the point defect thermodynamics in NiAl alloys. A particular motivation for this study is due to the expected elimination of structural vacancies on the Al-rich side at high pressure. We employ the density functional theory to compute point defect energies as a function of pressure, which are in turn used as input to the Wagner-Schottky model. We find that at about 200 kbar a change in the constitutional defect from V Ni to Al Ni does take place. The extension of the Wagner-Schottky model by introducing elastic interactions between defects leads to the prediction of a qualitatively new phenomenon in the system, namely the appearance of an isostructural phase transition terminated at a critical point. Similar behaviour is expected in some other ordered off-stoichiometric compounds.

Keywords

Point Defect Local Density Approximation Formation Enthalpy Substitutional Solid Solution NiAl Alloy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • Alexander Y. Lozovoi
    • 1
  • Ali Alavi
    • 1
  • Pavel A. Korzhavyi
    • 2
  • Michael W. Finnis
    • 1
  1. 1.Atomistic Simulation Group, School of Mathematics and PhysicsThe Queen’s University of BelfastBelfastNorthern Ireland, UK
  2. 2.Condensed Matter Theory Group, Physics DepartmentUppsala UniversityUppsalaSweden

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