Glasses of lithium fluoroborate of the composition LiF 15%–B2O3 85% with increasing CuO as added
dopant were prepared and characterized by combined optical and FTIR spectroscopy before and after
gamma irradiation. The optical spectrum of the undoped glass reveals strong UV absorption with two distinct
peaks at about 235 and 310 nm and with no visible bands. This strong UV absorption is related to
the presence of unavoidable trace iron impurity (Fe3+) within the materials used for the preparation of
this glass. After irradiation, the spectrum of the undoped glass shows a decrease of the intensity of the
UV bands together with the resolution of an induced visible broad band centered at about 520 nm.
The CuO doped glasses reveal the same UV absorption beside a very broad visible band centered at
780 nm and this band shows extension and splitting to several component peaks with higher CuO contents.
Upon gamma irradiation, the spectra of all CuO-doped glasses reveal pronounced decrease of their
intensities. The response of irradiation on the studied glasses is correlated with suggested photochemical
reactions together with some shielding effect of the copper ions. The observed visible band is related to
the presence of copper as distorted octahedral Cu2+ ions.
Infrared absorption spectra of the prepared glasses show repetitive characteristic triangular and tetrahedral
borate units similar to that published from alkali or alkaline earth oxides B2O3 glasses. A suggested
formation of (BO3/2F) tetrahedral units is advanced through action of LiF on B2O3 and these suggested
units showing the same position and number as BO4 tetrahedra.