As part of a study of the effect of impurities in heavy metal fluoride glas
ses on scintillation yield, we have examined the effects of melting atmosph
ere and base glass composition on the redox state of iron. The Fe3+ state o
f this transition metal absorbs in the near ultraviolet and hence affects t
he emission of the Ce3+ ion at 325 nm. The interactions between Fe2+/Fe3+ a
nd other multivalent species, particularly indium and cerium, have been stu
died. Cerium additions aid the reduction of iron to the Fe2+ state; the eff
ect of indium is similar but smaller. (C) 1999 Published by Elsevier Scienc
e B,V. All rights reserved.