The dependence of thermoluminescence of LiF:Mg,Cu,Si on sintering temperatures and dopants concentrations

Comparative studies on radioluminescent and thermoluminescent spectra of LiF:Mg,Cu,P and LiF:Mg,Cu,Si

The influence of various annealing treatments on radioluminescent (RL) and thermoluminescent (TL) spectra of LiF:Mg,Cu,Si and LiF:Mg,Cu,P was investigated. The TL and RL emission bands for LiF:Mg,Cu,P are not the same; however, the emission band peaking at ∼383 nm is predominant in the TL and RL emission for LiF:Mg,Cu,Si. With the increase in annealing temperatures in the range of 240-300°C, for LiF:Mg,Cu,P, the intensity of TL decreases much more rapidly than that of RL. For LiF:Mg,Cu,Si, the area ratios of the two bands of RL and TL remain constant within experimental errors. It suggests that there is a significant decrease in the concentration of recombination centres in LiF:Mg,Cu,P after the annealing, in addition to the decrease in trapping centres, the recombination centres for main TL emission and RL emission in LiF:Mg,Cu,Si are the same, and the recombination centres for TL emission and RL emission in LiF:Mg,Cu,P are not the same. P is a more effective dopant than Si.

Further studies on the role of dopants in LiF:Mg,Cu,Si thermoluminescent material

The 3-D thermoluminescence spectra and glow curves of LiF:Mg,Cu,Si, LiF:Mg,Cu, LiF:Mg,Si and LiF:Cu,Si with low concentrations of Mg and Cu were measured and were compared with those with high concentrations to investigate further the role of dopants in LiF:Mg,Cu,Si material. The shape of glow curves of the four samples is similar; however, LiF:Cu,Si sample had no Mg dopant. It is concluded that the TL emission to be from self-trapped excitons in LiF, and this emission could be enhanced and altered by Mg, Cu and Si dopants in LiF:Mg,Cu,Si; all three dopants are necessary to obtain the bright TL emission and may be involved in the luminescence process; Mg seems to be the most essential dopant and Cu is involved in the trapping although the role of Mg dominates; both Cu and Si play a role in the main emission process and Cu also plays a role in reducing the emission around 610 nm.