Thermoluminescent response and kinetic parameters of Eu3+-doped LiF crystals exposed to X-rays

Abstract

In the present work pure and Eu3+-doped LiF crystals were synthesized through co-precipitation method and the effect of Eu3+ concentration on the thermoluminescent (TL) response is reported. A cubic crystalline phase was determined by XRD for all synthesized samples. The photoluminescence spectra as well as UV–vis absorbance were also analyzed and four emissions bands centered at 592nm (5D0 → 7F1), 614nm (5D0 → 7F2), 652nm (5D0 → 7F3) and 698nm (5D0 → 7F4) have been observed. The TL response to X-ray irradiation was studied for an exposition of 43R during a total time of 52s. The presence of Eu3+ in the samples enhanced the TL signal, due to the Eu3+ ions that are incorporated into the LiF crystalline lattice which promotes the formation of defects in the unit cell. The kinetic parameters (E, b, s) were calculated using the glow-curve shape method. Energy traps around E=1eV and frequency factors on the order s=108s−1 were obtained on average, regardless of the Eu3+ concentration. The host of LiF showed the higher characteristic energies and frequency factors, respectively. The 1.0mol% Eu3+-doped sample was found to have a sensitivity 5 times greater than the host of LiF. The good TL sensitivity to X- ray exhibited by the Eu3+-doped LiF crystals synthesized in this work, suggests that this material should be further studied with respect to other characteristics before being used as a radiation dosimeter.