EPR study of radicals produced by gamma-irradiation in marine mollusc (Venus sp.) fossils

Koseoglu R., Koksal F., Çiftçi E.

RADIATION EFFECTS AND DEFECTS IN SOLIDS, vol.159, no.8-9, pp.497-502, 2004 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 159 Issue: 8-9
  • Publication Date: 2004
  • Doi Number: 10.1080/10420150412331296862
  • Journal Name: RADIATION EFFECTS AND DEFECTS IN SOLIDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Page Numbers: pp.497-502
  • Keywords: EPR, mollusc, fossil, gamma-irradiation, free radicals, ELECTRON-SPIN-RESONANCE, CARBONATE DERIVED RADICALS, TOOTH ENAMEL, PARAMAGNETIC-RESONANCE, SULFITE RADICALS, ESR, SPECTRUM, SHELLS, CO2, DOSIMETRY
  • Ondokuz Mayıs University Affiliated: No

Abstract

In this study, gamma-irradiated marine mollusc (Venus sp.) fossils were investigated by electron paramagnetic resonance (EPR) at ambient temperature. Powder X-ray diffraction technique indicates that the Venus sp. fossils were made mainly of CaCO3. Before gamma-irradiation, the EPR lines of the powder of fossil samples showed the existence of Mn2+ (I = 5/2, 100% natural abundance) ions with g(av) = 2.0055 and A(av) = 9.4 mT gamma-Irradiation-induced additional defects in Venus sp. fossil were attributed to axial CO3- (gperpendicular to = 2.0171, g// = 2.0048), orthorhombic CO2- (g(x) = 2.0030, g(z) = 2.0018, g(y) = 1.9973, g(av) = 2.0007), freely rotating CO2- (g(iso) = 2.0007), isotropic SO2- (g = 2.0057), axial SO3- (g perpendicular to = 2.0036, g// = 2.0024) and isotropic SO3- (g = 2.0032) free radicals. The g-values of these free radicals were compared with the literature data belonging to similar defects.