Study of optically stimulated luminescence and calculation of trapping parameters of K2Ca2(SO4)3:Eu nanophosphor

Highlights: • K2Ca2(SO4)3:Eu nanophosphor was synthesized by chemical co-precipitation method. • TL and CW-OSL have been studied after annealing samples different temperatures. • TL glow curve is deconvoluted and trapping parameters are calculated. • The qualitative correlation between TL peaks and CW-OSL response have been investigated. • OSL response has linear behavior up to 1.0 kGy. K₂Ca₂(SO₄)₃:Eu nanophosphor was synthesized by chemical coprecipitation method and annealed at different temperatures from 400 to 900 °C. The nanophosphor annealed at 600 °C showed cubic structure with crystallite size ~25 nm. TEM shows morphology of K₂Ca₂(SO₄)₃:Eu nanophosphor was in the form of nanorods having diameter ~20 nm and length of ~100–200 nm. These samples were irradiated with gamma radiation for the doses varying from 10 mGy to 10 kGy and their Thermoluminescence (TL) and continuous-wave optically stimulated luminescence (CW-OSL) have been studied. CW-OSL response was found to be maximal for the sample annealed at 600 °C. The TL glow curve of the nanophosphor apparently showed a major peak at around 160 °C accompanied by three low intensity peaks at ~75, 215 and 285 °C. The traps responsible for all the TL peaks in K₂Ca₂(SO₄)₃:Eu were also found to be OSL sensitive. The qualitative correlation between TL peaks and CW-OSL response suggested that the traps associated with low temperature peaks are responsible for fast decay and the traps associated with the higher temperature peaks are responsible for slow decay of the OSL signal. OSL response showed linear behavior up to 1 kGy and saturated with further increase in the gamma dose. The wide OSL response makes studied K₂Ca₂(SO₄)₃:Eu nanophosphor a good candidate for high dose measurement.