Thermoluminescence of ZrO2 doped with Er2O3 induced by ultraviolet and x-ray radiation

This work investigates the thermoluminescent (TL) glow of Er2O3-doped ZrO2 sample, after separate irradiation with UV and synchrotron x-ray radiations. Experimental results indicate that, in addition to a major TL peak at 98 degrees C and a minor one at 205 degrees C, another minor peak appears at 135 degrees C. The intensity of two minor peaks, particularly the one at 135 degrees C, increases rapidly with the photon energy. Initial rise method is used to obtain the activation energies of 0.96 and 0.99 eV for 135 and 205 degrees C TL peaks, respectively. Moreover, the trap depth is theoretically estimated by invoking a HHe+2 like model in which an electron is trapped by an effective positive charge localized on an oxygen site but perturbed by two effective positive charges localized on a cation site. Derived theoretical trap depths, 0.95 and 0.97 eV, are in excellent agreement with experimental values. (C) 1999 American Institute of Physics. [S0021-8979(99)01712-0].