Iron-doped glass
This sample reveals the same strong UV-near visible absorption with four UV bands at 235, 310, 350 and 380 nm and a strong visible band at 480 nm.
Such strong and extended absorption bands are related to the presence of ferric ions and absorption due to Bi3+ ions as previously reached with the undoped glasses containing trace impurities beside the optical absorption show maintenance
and this stability is due to the high content of heavy Bi3+ ions which are assumed to shield the effect of gamma irradiation.
The decrease of the rest visible absorption can be related to the sharing of iron ions in the shielding process.