Activation volume and chemical environment of atomic vacancies in intermetallic compounds

M. A. Müller, W. Sprengel, J. Major, H. E. Schaefer

Research output: Contribution to journalConference article

11 Citations (Scopus)

Abstract

Positron annihilation spectroscopy was used to investigate the temperature, time and pressure dependence of the equilibration of the thermal vacancy concentration in B2-Fe61Al39 after fast temperature changes at elevated temperatures. A two stage equilibration process was observed with a migration enthalpy of H1VM = (0.8 ± 0.2) eV and H2VM = (1.7 ± 0.3) eV for a faster, initial process and a long-term, main process, respectively. For the main process a formation volume of VVF = (1.5 ± 0.3) Ω and a migration volume of VVF = (4.6 ± 1.1) Ω for thermal vacancies were determined. By employing coincident Doppler broadening studies it could be demonstrated for the first time for the model case of FeAl that thermal vacancies are formed on the transition metal sublattice.

Original languageEnglish
Pages (from-to)85-87
Number of pages3
JournalMaterials Science Forum
Volume363-365
Publication statusPublished - Jun 7 2001
Event12th International Conference on Positron Annihilation - Munchen, Germany
Duration: Aug 6 2000Aug 12 2000

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Keywords

  • Coincident Doppler broadening
  • Fe vacancies
  • Intermetallic compounds
  • Migration volume

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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