THERMOLUMINESCENCE AND ELECTRON-SPIN-RESONANCE OF ATOMIC HYDROGENS INCOESITE AND STISHOVITE, HIGH-PRESSURE PHASES OF SIO2

Thermoluminescence (TL) of coesite and stishovite has been measured af ter gamma-ray irradiation at room temperature from Co-60. Analysis of the first TL peaks at 205 degrees C indicates an activation energy, E( I) = 1.20 eV and a pre-exponential frequency factor, s = 1.3 x 10(12)H z; the second peaks are at 240 degrees C and at 255 degrees C giving E (II) = 1.27 eV and 1.32 eV for coesite and stishovite, respectively. E SR lines at g = 2.002 with A(perpendicular to) = 46 mT and A(parallel to) = 59 mT show the same isochronal annealing behavior with the same parameters of thermal stability as those of the first TL peaks. Other ESR lines at g = 2.002 with A(perpendicular to) = 50 mT and A(parallel to) = 53 mT are stable to high temperature. Atomic hydrogens, H-0, in densified amorphous and in crystalline parts are responsible for the ESR signals and the release of trapped H-0 leads to recombination with a hole center emitting the TL light.