Structural properties of the boro-bismuthate glasses containing gadolinium ions

The structural properties of the xGd2O3(100−x)[4Bi2O3·B2O3] vitreous system, with 0 ≤ x ≤ 30 mol% were investigated by FT-IR spectroscopy, density measurements and ab initio calculations.Increasing the gadolinium ion content in the studied glasses increases the density and the oxygen packing density and decreases the molar volume suggesting that the vitreous network becomes more tightly packed.FT-IR spectroscopy data reveal that Bi2O3 and B2O3 behave as network formers and are incorporated in the vitreous network as [BiO3], [BiO6], [BO3] and [BO4] structural units while the gadolinium ions play the network modifier role in these glasses.FT-IR and density data were used to establish the starting geometries of the ab initio computation for the structural model of the studied glasses.