Effect of lithium co-dopant on the thermoluminescence response of some phosphors

The effect of lithium co-dopant on the thermoluminescence of some TL phosph ors has been studied. These results show that lithium co-dopant when presen t in CaSO4:Dy, CaSO4,Tm, CaF2:Mn, MgB4O7:Dy, MgB4O7:Tm, MgB4O7:Tb, MgB4O7:M n, CaB4O7:Dy and CaB4O7:Tm thermoluminescent phosphors induces higher lumin escence efficiency either due to better incorporation of activator ions or due to improvement in energy transfer processes. Go-doping with Li of the a bove given phosphors resulted in increasing the TL sensitivity from 1.2 to 3.4 times, when compared with that of the TL phosphors without lithium co-d opant. The effect of co-doping with lithium impurities on the thermoluminescence o f various TL phosphors is also studied in dependence of Li concentration, o f the chemical form of added lithium compounds and of the method of additio n of Li co-dopant during the TL phosphor preparation. It is observed that the addition; of Li co-dopant induces in some TL phosph ors enhancement of the lower temperature peak which is correlated with the increase of TL sensitivity. The high TL output of these TL phosphors could be used in dosimetric practice for special short-term measurements. (C) 200 0 Elsevier Science Ltd. All rights reserved.