Structural properties of Li-borate glasses doped with Sm3+ and Eu3+ ions

A Li-borate glass system doped with samarium and europium has been prepared by a conventional melt quenching technique. Europium content was kept constant at 0.01 mol%. The general formula was xSm2O3 + (100 - x) [0.84B2O3 + 0.15Li2O + 0.01Eu2O3] where x = 0.1, 0.2, 0.5, 0.6 and 0.7 mol%. The density was measured and the corresponding molar volume was evaluated .The former was found to increase by increasing Sm while the later exhibits opposite trend. The average optical basicity, Λth, electron negativity χ2av and electron polarizability α2- were calculated for the prepared compositions. Infrared spectra were obtained at room temperature for the prepared glasses before and after γ irradiation. The results showed that the three main appeared bands are most likely due to the bending and/or stretching vibration of both tetrahedral BO4 and triagonal BO3 borate units. ESR spectra were recorded at room temperature before and after γ-irradiation. It was found that the oxygen atoms of BO3 units are responsible for the formation of the hole paramagnetic centers after irradiation in the glass matrix.