Thermally stimulated luminescence of X-ray irradiated sodium borate glasses doped with cerium(III) and samarium(III)

Thermally stimulated luminescence has been observed in X-ray irradiated sodium borate glasses codoped with Ce3+ and Sm3+. The emission wavelength corresponds to the 5d --> 4f transition of Ce3+. X-ray irradiation leads to the ionization of Ce3+ to form Ce4+ and an electron, which is released from the Ce4+ and trapped by Sm3+. Thermal stimulation excites this electron, which transfers to the 5d level of Ce4+. The radiative relaxation of this electron to the 4f state gives rise to the observed emission. In contrast, point defects such as a non-bridging oxygen hole center and an electron trapped near Na+ induced by the X-ray irradiation contribute to the thermally stimulated luminescence in glasses doped with only Ce3+. The thermally stimulated emission intensity increases linearly with an increase in the X-ray irradiation time up to 1 h for 25Na(2)O . 75B(2)O(3):Ce, Sm glass, suggesting that this glass is a promising material for radiation dosimetry.