Photostimulated luminescence in borate glasses doped with Eu2+ and Sm3+ ions

In this article we report on photostimulated luminescence in sodium borate glasses doped with Eu2+ and Sm3+ ions. When the X-ray irradiated glasses were excited by a He-Ne laser (633 nm), photostimulated luminescence at 470 nm due to the 5d-4f transition of Eu2+ ions was observed. X-ray absorption spectra showed that some ions of Eu2+ were converted into Eu3+, while Sm3+ ions remained unchanged upon irradiation with X-rays. By comparison with the mechanism of photostimulated luminescence in BaFBr-Eu2+, the luminescence is proposed to result from the photostimulated recombination of holes and electrons at traps which leave electrons in a long-lived excited state. (C) 1997 Elsevier Science B.V.