Thermoluminescence emission on lead oxychloroborate glasses under UV exposure.

Glassy materials were prepared using two different systems: 50B2 O3 - (50 - x)PbO - xPbCl2, with x = 0, 2 and 5 in mol % (System BPCl-I) and 50BO1.5 - (50 - x)PbO - xPbCl2 with x = 0, 2, 5 and 7 in cationic % (System BPCl-II). Structural and optical characterization showed that PbCl when substituted for PbO changed the structure of the glass network by replacing nonbridging oxygens for chlorine ions. This substitution also caused a change in the number of defects responsible for thermoluminescence (TL) emission (electrons and hole trap centres). Thermoluminescence emissions were observed for the first time in lead oxychloroborate glasses after exposure to UV radiation. Sample BPCl-I-2 (x = 2 from System I) demonstrated better TL emission compared with other glass samples. One intense peak in the glow curve, centred at ~122°C followed by a shoulder at ~180°C, was highly sensitive to UV radiation. There were also good linear responses at dose range ~0.4 to ~2 J/cm2 for the first peak (low temperature) and ~0.4 to ~4 J/cm2 for the second peak (high temperature).