Role of Mn as a co-dopant in CaSO4:Mn,Pr TL phosphor

CaSO4:Pr, CaSO4:Mn and CaSO4:Mn,Pr thermoluminescence (TL) phosphors have been prepared and their TL glow curves and TL emission spectra are recorded. TL emission bands at 360, 440, 490 and 610 nm were observed for CaSO4:Pr in the scanned range. Co-doping of Mn in CaSO4:Pr enhances its TL sensitivity. TL sensitivity of CaSO4:Mn,Pr (0.5, 0.1 mol%) is about 47 times that of CaSO4:Pr (0.1 mol%). TL emission band at 500 nm was observed for CaSO4 doped with Mn. TL emission of 220 °C TL peak in CaSO4:Mn,Pr consists predominantly of 500 nm band. The presence of Mn2+ emission in 220 °C peak in CaSO4:Mn,Pr is because of transfer of electron-hole recombination energy to Mn2+ ions during TL readout. The presence of weak Pr3+ emission, along with Mn2+ emission, indicates that Pr3+ ions compete in absorbing the electron-hole recombination energy.