Thermally stimulated luminescence from X-irradiated Gd2SiO5:Ce, measured in the interval 300-700 K, is characterized by a main glow peak near 390 K and weaker maxima near 420, 490 and 550 K. Analysis of the well-resolved principal peak shows that it obeys first-order kinetics with thermal activation energy 1.16 eV and frequency factor 3.17 x 10(14) s(-1). The glow curve and peak parameters are similar to those found in cerium-doped M2SiO5 (M = Lu, Y, Yb, Er) and undoped Lu2SiO5. For these latter samples, it has previously been shown that the defect responsible For the principal peak (similar to 375 K) is intrinsic and common to these C2/c-structured oxyorthosilicates. The present results demonstrate that the defect is also common to Gd2SiO5:Ce, which possesses P2(1)/c symmetry, and is likely associated with the configuration of oxygen ions in the vicinity of the host lanthanide ions. An oxygen ion vacancy is a plausible candidate for this defect. (C) 2001 Elsevier Science Ltd. All rights reserved. [References: 15]
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