Temperature experiments on mollusc samples: an approach to ESR signal identification

Powered mollusc samples, which were irradiated with γ rays at room temperature, were analysed by ESR spectrometry at different temperatures ranging from 293 to ∼ 100 K. Gamma-ray irradiations, sometimes preceded by a thermal treatment at 1800C, were also performed at 77 K and at 140-1800C. From these experiments and from a study on non-powdered samples, it is concluded that the mollusc ESR spectrum is principally due to five paramagnetic species with the following values: (1) g = 2.0057; (2) gparallel=2.0033 and gperpendicular=2.0031 (the narrow g=2.0032 line); (3) gparallel=2.0017 and gperpendicular=2.0020 (the g=2.0019 line); (4) g=2.0007; (5) g1=2.0032, g2=2.0016 and g3=1.9973 (CO2-). (author)