Ultraviolet and visible transmission spectra of heavy germanate glasses containing Sn2+ and Ce3+

Abstract Six heavy germanate glasses containing GeO 2 , Gd 2 O 3 , BaO, SnO 2 and La 2 O 3 are prepared. Ultraviolet and visible transmission spectra are measured and compared. Special attention is paid to the UV absorption edges of these glasses which prove moderate and suitable for hosting scintillating Ce 3+ activators. Red shifts of UV absorption bands assigned to the solute Sn 2+ and Ce 3+ in these glasses are observed. Reasonable explanations are given from the viewpoint of different mechanisms of UV absorption referring to the different types of metal ions existing in the glass network. The relationship between such red shift and compositions of glass matrices is fully discussed in terms of the so-called ‘optical basicity’ of glasses.