Synthesis, optical and solid NMR studies of strontium titanate borosilicate glasses doped with TeO2

Various glass compositions were synthesized in the glassy compound (60-x)[SrTiO3]-39[2SiO(2)B(2)O(3)]-(1 + x)TeO2, (x = 0, 2, 4, 6 and 8) by rapid melt-quenching method. X-ray diffraction (XRD) results show amorphous characteristics of the prepared glasses. Structural, optical and solid-state nuclear magnetic resonance (NMR) characterizations were carried out using different spectroscopic techniques. The calculated optical band gap values were obtained in the range of 3.31 eV-3.48 eV. The Urbach energy, E-U and skin depth, delta were calculated; E-U was found to be increased from 0.284 to 0.296 eV with increasing doping concentration of TeO2. B-11-MAS-NMR and Si-29-MAS-NMR measurements recommend the formation of non-bridging oxygen within glassy network.