High temperature thermolumineseence of BaFCl:EU2+ X-ray storage phosphor

Thermoluminescence (TL) of Eu2+-doped BaFCl polycrystalline powders X- ray irradiated at room temperature show several TL peaks at 364 K, 408 K, 470 K, 524 K and 646 K. Thermally activated recombination processes responsible for TL have been studied using complementary techniques as TL and its bleaching, diffuse reflectance, X-ray excited luminescence (XL) and photostimulated luminescence (PSL). Experimental results indicate that F(Cr) centres are the dominant electron trap centres, the Eu2+-trapped hole aggregate centres playing the role of recombination centres. The 470 K and 646 K TSL glow peaks are assigned to the recombination inside the triple aggregates (Eu2+ - hole centre - F(Cl-) centre). The remaining 408 K and 524 K TL peaks are tentatively assigned to recombination between F centres and double aggregates (Eu2+ - hole centre). (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.