Thermoluminescence studies of Zinc Borate (ZnB 2 O 4 ) phosphor doped with rare earths for dosimetric aspects.

A series of ZnB 2 O 4 phosphors doped with different concentrations of Eu & Dy (0.05 0.1, 0.2, 0.5, 1.0 mol %) and co-doped with Ce (1, 2, 5, 7, 10 mol %) respectively were prepared via Solid State Reaction technique and the thermoluminescence (TL) behaviour of gamma rays irradiated samples was studied. The synthesized samples were irradiated to γ-rays for dose range 0.03 kGy to 1.20 kGy. The TL intensity variation with dose, dopant concentration, effect of co-doping were studied. TL response curve for ZnB 2 O 4 :Eu 3+ and ZnB 2 O 4 : Dy 3+ , ZnB 2 O 4 :Eu 3 , Ce 3+ and ZnB 2 O 4 :Dy 3+ , Ce 3+ phosphor was observed. It was revealed that ZnB 2 O 4 :Eu 3+ shows the linear TL behaviour for the dose 0.03 kGy to 1.20 kGy and ZnB 2 O 4 : Dy 3+ shows linearity for gamma dose range 0.03 kGy to 0.10 kGy. Further, fading for all the samples was observed to be less than 10 % for a storage period of 30 days. In addition to this, the trapping parameters, especially activation energies were evaluated using Ilich Method and Initial Rise method. The activation energy values obtained from both the methods were in complete agreement with each other.