A post annealing effect on SrF2 nano particles: Structural, morphological, functional and dosimetric properties

We report structural, morphological, functional and dosimetric properties of strontium fluoride (SrF2) nanophosphor synthesized by chemical co-precipitation method. The synthesized SrF2 nanophosphors are annealed at different temperatures. Samples annealed at 700 °C are observed to show optimum thermoluminescence and they are used for further processing. X-ray diffraction reveals a cubic structure having crystallite size of ∼21 nm for pristine samples and enhanced size after annealing treatment. Field emission scanning electron microscopy (i.e. FESEM) reveals growth of uniform SrF2 nanophosphors with increase in grain size for 700 °C which is in good agreement with the XRD result. In addition, we have focused on dosimetric properties and have recorded very good results of thermoluminescence (TL) glow curve, dose-response linearity, fading and trapping parameters etc. Based on the experimental results, thermoluminescence glow curve is observed at a deeper side (i.e. 210 °C) and dose-response range is achieved up to 1 kGy. Density of states obtained from density functional based calculations indicate emergence of an extra state on introduction of vacancy point defect. The new state is found to be a result of hybridization of F: d and Sr: s states, and F: p and Sr: d and f states for F and Sr vacancy defects respectively. Therefore, virgin (without any doping) nanophosphors show potential as a powerful independent thermoluminescent dosimeter (TLD) with the vacancy defects playing a key role. •A chemically synthesized virgin SrF2 phosphor was studied experimentally as well as computationally.•Annealing generates point defects which also alter the band gap nature.•DOS results revealed the emergence of an extra state with the introduction of a vacancy point defect.•A detailed study on the effect of annealing treatment of SrF2 phosphor for radiation dosimetry.