X-ray excited luminescence and photoluminescence of Bi4(GeO4)3 glass-ceramics

Bi4(GeO4)3 glass materials have been characterized by X-ray excited luminescence, photoluminescence and cathodo-luminescence measurements. The materials were obtained by crystallization at different temperatures and their spectroscopic parameters were compared before and after crystallization. Thermoluminescence curves recorded after electron irradiation of BGO glass behave similarly to BGO crystals, showing several peaks between 408 K (135 oC) and 610 K (337 oC). The differences between the Bi4(GeO4)3 crystals and glass materials are believed to result from the random distribution of GeO4 tetrahedra around Bi3+ ions which influences the photoluminescence and TL parameters. The CL images of glass-ceramic samples obtained by partial crystallization at 600 oC show luminescent crystalline structures, which are probably responsible for the increase in scintillation efficiency.