Point Defects in NiAl Alloys Under Pressure

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


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.


Point Defect Local Density Approximation Formation Enthalpy Substitutional Solid Solution NiAl Alloy 
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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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