(c) Many of 3d TM ions are observed to share in the maintenance
of the spectral curves upon irradiation and they are
assumed to shield in the same way as the presence of heavy
metal ions (Bi3+, Pb2+) causing retardation of the effect of
irradiation.
(d) The glasses containing 3d transition metal ions within the
doping level can be utilized to act as sensitive radiation
dosimeter or as shielding candidate.
Conclusion
Optical absorption of undoped binary bismuth silicate glass reveals
strong and extended UV-near visible absorption bands which
are attributed to the presence of unavoidable trace iron (Fe3+) ions
as impurities within the raw materials beside the absorption of
main constituent bismuth (Bi3+) ions present in high content
(Bi2O3 70 mol%). Such strong and extended UV-near visible suppress
any formation of UV absorption due to the presence of 3d
transition metal ions-doped (0.2%) within the studied bismuth silicate
host glass. The visible absorption due to each respective TM
ion appears in its characteristic bands. The presence of high content
of Bi2O3 is observed to cause shielding towards gamma irradiation
as presented by the general constancy of the optical spectra.
Infrared absorption spectra of undoped and 3d TM ions-doped
bismuth silicate glasses exhibit characteristic vibrational modes
due to both silicate and Bi-O present as BiO6 and/or BiO3 units.
Gamma irradiation is observed to have no effect on the IR vibrational
modes due to the stability of the glass network.