Properties of methyl radical trapped in amorphous SiO2 and in natural SiO2-clathrate Melanoflogite

Risultato della ricerca: Article

6 Citazioni (Scopus)

Abstract

We report an experimental investigation by electron paramagnetic resonance (EPR) on methyl radical (CH3 • )observed in γ-ray irradiated high-purity amorphous silicon dioxide (a-SiO2) and in a polycrystalline sample ofMelanophlogite, a rare natural form of SiO2-clathrate. From the analysis of the EPR spectra we estimate the correlationtime of the hindered rotational motion of CH3 • molecules at T=77 K in the two different materials. Thisphysical quantity gives a quantitative measure of the freedom of motion of CH3 • molecules trapped in the twosolid systems, putting forward relevant information on the properties of the cavities/interstices inwhich the radicalsare confined. In particular, our data suggest that in a-SiO2 the CH3 • molecules are trapped in interstices withdiameter significantly lower than about 5.7 Å, which is the size of the smaller cavity involved in the crystallinestructure of Melanophlogite.
Lingua originaleEnglish
pagine (da-a)9-12
Numero di pagine4
RivistaJournal of Non-Crystalline Solids
Volume361
Stato di pubblicazionePublished - 2013

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

Cita questo