Positron annihilation study of electron-irradiated silicon-germanium bulk alloys

Atsuo Kawasuso, Sohei Okada, Ichiro Yonenaga, Tatsuya Honda, Masashi Suezawa

Research output: Contribution to journalArticlepeer-review


As-grown and electron-irradiated SixGe1-x bulk crystals (x=0-0.82) have been studied using positron annihilation spectroscopy. Bulk positron lifetime and Doppler parameters were found to change from the value for Ge to that for Si with increasing Si fraction x. However, the dependence was non-monotonic at around x=0.20. Theses results seem to be correlated with the abrupt change of the band gap energy of SixGe1-x. After 3 MeV electron irradiation, vacancy-type defects giving rise to the lifetime of 280 ps and 330 ps were detected for 0.63 ≤ x ≤ 0.82 and 0.20 ≤ x ≤ 0.40. However, no vacancy components were observed for x < 0.20. The composition-dependent vacancy production was interpreted in terms of the thermal stability of vacancies with the composition. Through the annealing experiment for the Si0.82Ge12 specimen after irradiation, it was found that vacancy-clustering upon heating was suppressed and considerably shifted to high temperatures as compared with the case of Si.

Original languageEnglish
Pages (from-to)127-132
Number of pages6
JournalMaterials Science Forum
Issue numberPART 1
Publication statusPublished - 1997


  • Annealing
  • Doppler broadening
  • Electron irradiation
  • Positron lifetime
  • SiGe
  • Vacancy

ASJC Scopus subject areas

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


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