Effect of Eu³⁺ impurity concentration and <i>γ</i>-irradiation on the photoluminescence of LiB₃O₅:Ag,Eu triborate glass

The results of studies of the doped triborate glass <i>L</i><i>i</i><i>B</i>₃<i>O</i>₅:<i>A</i><i>g</i>,<i>E</i><i>u</i> are presented, in particular, excitation spectra of the photoluminescence, emission, and absorption spectra depending on the Eu concentration (0.5, 1.0, and 1.5 wt.%) at a fixed Ag concentration (1.0 wt.%), before and after <i>γ</i>-irradiation with doses of 5 and 10 Gy. In the photoluminescence spectra, bands associated with <i>A</i><i>g</i>⁺ centers and europium ions are observed. The silver dopant forms the <i>A</i><i>g</i>⁺ luminescence center with an emission maximum of 290 nm, while the europium dopant forms the luminescence center associated with <i>f</i>-<i>f</i> transitions in <i>E</i><i>u</i>³⁺ in the range of 575-675 nm. The nature of the luminescence band at 380 nm is discussed, which can be associated with <i>E</i><i>u</i>²⁺ ions. It was found that the concentration of Eu impurity significantly affects the luminescence intensity in the UV region of the spectrum. After <i>γ</i>-irradiation, the intensity of the 380 nm peak under 310 nm excitation exhibits a clear dose dependence that is dependent on the Eu concentration. The possible mechanisms of the change in radiation intensity are discussed.