Structural analysis and physical properties of iron-molybdenum lithium-borate glasses

Samples of iron-molybdenum lithium-borate glass were prepared and investigated. Infrared and Moessbauer effect spectroscopy were employed to study the structure of these glasses. Density, molar volume, magnetic susceptibility and electrical resistivity were also measured. It can be concluded that different structural groups, such as BO3, BO4, MoO4, MoO6, FeO4 and FeO6 were detected in the glass network. The dependence of the ratio [Fe2+/Fe3+] on lithium concentration was clearly observed. The magnetic susceptibility measurements indicated that all these glasses possess paramagnetic character, and the highest magnetic susceptibility value appeared in the sample that contained 20 mol% Li2O. The change of dielectric constant and loss with increasing of lithium ions content could be attributed to the assumption that Fe and Mo ions tend to assume network-forming position in the glass compositions studied. And the change of the ac conductivity is attributed to the hopping mechanism of conduction