ESR, TL, and fluorescence correlation in BaSO4:Eu,P thermoluminescent phosphor

Abstract

Our earlier ESR studies on the thermoluminescent (TL) phosphor BaSO4:Eu, P indicated the involvement of two SO2- radicals in the TL process and co-doping BaSO4:Eu (0.5 mol%) with phosphorus (0.2 mol%) enhanced its TL efficiency by 5.3 times. The present study indicates an almost lone-to-one correlation in the growth of TL (488 K peak) and ESR (SO2- (B) radical) intensities in the tested range of 1 to 1000 Gy. When the synthesised BaSO4:Eu, P was thermally treated in the temperature range 673 to 1273 K, the TL, ESR, and fluorescence intensities yielded maxima at 1173 K. These results give further support to our earlier speculation that the enhancement of TL sensitivity in BaSO4:Eu, P results from an increased intake of divalent europium into the lattice.