The glassy system under investigation is y Li2O – 25 ZnO – 49.9 B2O3 – (25–y) Na2O – 0.1 Cr2O3, where y = = 0,
10, 20, 25 mol%, and it was prepared via traditional melt quenching technique. The optical absorption spectrum
of alkali borate glass containing Cr ions reveals a decrease in Cr6+ contributions as the lithium content increases.
The strength of crystal field decreases, while the value of both Racah parameters B and C clearly follow a reverse
behavior as the content of Li2O increases. The chromium ion has a more ionic environment, and larger numbers
of electrons are localized on the D-shell. The obtained ESR signals pointed out the presence of both Cr6+and
Cr3+states in the host borate glass. FTIR spectra indicated the existence of some bonds, denoting B-O bonds
vibrations from BO3 as well as BO4 units. An estimation of the fraction N4 has been conducted, utilizing the
characteristic parameters of IR. Glass samples were influenced by γ- Irradiation, and a minor change occurred in
bond angles and lengths of the structural units of borate. This proves the minor diversity of the IR bands
intensity. |
