ELECTRON-SPIN-RESONANCE, THERMOLUMINESCENCE AND FLUORESCENCE STUDIES ON BASO4-EU AND BASO4-EU, P THERMOLUMINESCENT PHOSPHORS

The paramagnetic radicals formed in the TL phosphors BaSO4:Eu and BaSO 4:Eu, P have been studied using the technique of ESR. Two radicals, as signed to SO2-, were observed at room temperature. One of them exhibit s a hyperfine interaction with a nearby cation. Step annealing measure ments suggest a connection between these radicals and the TL glow peak s at 170 and 215 degrees C. Co-doping BaSO4:Eu with phosphorus enhance d its TL efficiency. ESR and fluorescence emission measurements indica te that the enhancement results from an increased intake of divalent e uropium into the lattice.