| Summary: | Lanthanum tellurite (95-x)TeO2-5La2O3-xTiO2, (x = 0 - 20 mol%) glasses were prepared by the melt-quenching method. Elastic and structural properties of the glasses were studied by measuring sound velocity using the pulse-echo-overlap technique and Fourier Transform Infrared (FTIR) spectroscopy, respectively. In addition, the glass transition temperature, Tg was investigated using Differential Scanning Calorimetry (DSC) measurements. Both independent moduli (CL and μ) and related elastic moduli such as bulk modulus (Ke), Young's modulus (E), hardness (H) and Debye temperature (θD) were observed to increase gradually for x < 15 mol% followed by a large increase at x = 20 mol% addition of TiO2. The results obtained showed that this glass system becomes more stable, rigid and stiffer with addition of TiO2. Structural analysis showed increase in bridging-oxygen (BO) compared to non-bridging oxygen (NBO). Tg increased with addition of TiO2 and confirms the increasing rigidity of the network. Theoretical analysis using bulk compression and ring deformation models showed a gradual increase in ratio of ideal bulk modulus compared to experimental bulk modulus, Kbc/Ke for x < 15 mol% before a sudden drop at x = 20 mol%. The drop indicates decrease in ring deformation or bending. Although some deformation or bending may take place during compression, the main compression mechanism was still mainly isotropic ring compression. © 2014, National Institute R and D of Materials Physics. All right reserved.
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