Maximum incorporation of oxygen radicals, O- and O2-, into 12CaO·7Al2O3 with a nanoporous structure

Katsuro Hayashi, Satoru Matsuishi, Naoto Ueda, Masahiro Hirano, Hideo Hosono

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84 Citations (Scopus)


The effects of oxygen partial pressure (pO2) up to 400 atm on the generation of active oxygen radicals in 12CaO·7Al2O3 (C12A7) was examined using a hot isostatic pressing technique. Concentrations of superoxide (O2-) and oxygen anion radicals (O-), which were analyzed from a combination of electron paramagnetic spin resonance (EPR) and Raman spectroscopy, increased with pO2. The total concentration of the radicals reached 1.7 × 1021 cm3, which is comparable to the theoretical maximum, confirmed that dominant radical incorporation process is O2- (cage) + O2 (atmosphere) → O- (cage) + O2- (cage). The radical incorporated C12A7 has a large magnetic susceptibility that obeys Curie's law down to 2.5 K without magnetic ordering, although a weak exchange interaction was suggested by the line narrowing of the EPR signal.

Original languageEnglish
Pages (from-to)1851-1854
Number of pages4
JournalChemistry of Materials
Issue number9
Publication statusPublished - May 6 2003
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry


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