Raman spectrum, quantum mechanical calculations and vibrational assignments of (95% α-TeO2/5% Sm2O3) glass

Chozen system of tellurite glasses doped with rare earth oxides (95% α-TeO2 + 5% Sm2O3) was prepared by melt quenching. Consequently, the Raman spectrum (150–1250 cm−1) of the modified tellurite have been recorded. As a continuation to our normal coordinate analysis, force constants and quantum mechanical (QM) calculations for tbp TeO44− (triagonal bipyramid, C2v) and TeO3+1; Te2O76− (bridged tetrahedral), we have carried out ab initio frequency calculations for tpy TeO32− (triagonal pyramidal, C3v and Cs) and tp TeO32− (triagonal planar, D3h) ions. The quantum mechanical calculations at the levels of RHF, B3LYP and MP2 allow confident vibrational assignments and structural identification in the binary oxide glass (95% α-TeO2 + 5% Sm2O3). The dominant three-dimensional network structures in the modified glass are triagonal pyramidal TeO3 with minor features of short range distorted tbp TeO4 and bridged tetrahedral unit of TeO3+1, leading to a structure of infinite chain. Therefore, α-TeO2/Sm2O3 (95/5%) glass experience structural changes from TeO4 (tbp); Te2O7 (TeO3+1) → TeO3 (tpy).