Estimation of pore size of porous materials by positron annihilation lifetime measurement

Kenji Ito, Yasuhiro Yagi, Shingo Hirano, Masaru Miyayama, Tetsuichi Kudo, Akira Kishimoto, Yusuke Ujihira

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)


Pore size of several porous materials such as zeolites (MCM-41 and MCM-48) and highly fined grain aggregates of zirconia was estimated by means of positron annihilation lifetime measurement. Observed lifetimes of ortho-positronium (over ∼20 ns, τ4 and τ5) correspond to the meso-pore sizes assessed by conventional porosimetries due to a nitrogen physisorption and a mercury porosimetry. The long-lived lifetime components included an unassigned lifetime component (τ5), which was not detected by the other porosimetry. The observed ortho-positronium lifetimes are correlated to the mean size of pores. A relation between relative intensities of the long-lived ortho-positronium components (I4 and I5) and specific surface areas is discussed and a variation of a numerical concentration of pores is correlated to the change of the particle sizes of the zirconia aggregates.

Original languageEnglish
Pages (from-to)123-127
Number of pages5
JournalJournal of the Ceramic Society of Japan
Issue number2
Publication statusPublished - 1999
Externally publishedYes


  • Meso pore
  • Micro pore
  • Nondestructive analysis
  • Pore size
  • Porous material
  • Positron annihilation
  • Positronium

ASJC Scopus subject areas

  • Ceramics and Composites
  • Chemistry(all)
  • Condensed Matter Physics
  • Materials Chemistry


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