• A M EMARA

      Articles written in Bulletin of Materials Science

    • Evaluation of the elastic properties of monovalent oxides using TeO$_2$-based glasses

      A M EMARA S F MANSOUR M Y HASSAAN El SAYED YOUSEF

      More Details Abstract Fulltext PDF

      Quaternary tellurite glasses with composition 75TeO$_2$–5WO$_3$–15Nb$_2$O$_5$–5M$_x$O$_y$ in mol%, where M$_x$O$_y$ =(Na$_2$O, Ag$_2$O, ZnO, MgO, CuO, NiO, TiO$_2$, MnO$_2$), were prepared by the normal melt-quenching method. The ultrasonic velocities (longitudinal and shear) were measured in these glasses using the pulse-echo technique at room temperature. Their elastic moduli, microhardness and Debye temperature were calculated and discussed in terms of the modifier’s ionicity and quantitatively in terms of number of bonds per unit volume and the cross-link density. In this study, the values of ultrasonic velocities, elastic moduli, Debye temperature and microhardness were found to be strongly dependent on three factors, namely: (i) modifier’s ionicity; (ii) trigonal pyramid (TeO$_3$)/trigonal bipyramid (TeO$_4$) ratio; and (iii) glass transition temperature $T_g$. We used the Makishima and Mackenzie’s model to calculate the theoretical elastic moduli and to indicatethat the experimental values were in good agreement with the theoretical values.

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