Effect of annealing and fuel type on the thermoluminescent properties of Li2B4O7 synthesized by Solution Combustion Synthesis

The objective of this work is to investigate the effect of annealing and fuel type on the thermoluminescent (TL) properties of Li2B4O7 (LBO) synthesized by Solution Combustion Synthesis. In this study, LBO:Cu,Ag was synthesized using four fuel combinations of urea, a urea/ammonium nitrate mixture, glycine, and a glycine/ammonium nitrate mixture. Annealing was performed at temperatures from 800 °C to 900 °C for periods from 20 min to 120 min. The samples were then studied by X-ray diffraction (XRD) and TL. The results show that, among the parameters investigated, the annealing temperature and duration are the main parameters affecting the TL sensitivity (up to a factor of 2), which may be correlated with crystallite sizes. We also observed some effect of annealing on light sensitivity, but the effect was at most a reduction from a TL loss of ∼20% to ∼2% for 3 h exposure to room light. The main conclusion is that Solution Combustion Synthesis is an appropriate method to obtain LBO:Cu,Ag suitable for temperature sensing applications, the post-synthesis annealing regime being one of the parameters that can affect the signal intensity and, to a lesser extent, the light sensitivity.

► Effect of fuel type and annealing of synthesized Li2B4O7:Cu,Ag was investigated.
► Fuel had little effect on TL properties or crystal structure.
► Annealing had the largest effect on TL, increasing intensity by a factor of 2.
► Proper annealing reduced TL loss from ∼20% to ∼2% for 3 h room light exposure.