داریوش سوری

Abstract In this research, xMoO3–( 60 − x)V2O5–40TeO2 oxide glasses with (0 ≤ x ≤ 60) have been prepared by common meltquenching method. Differential scanning calorimetry (DSC) at different heating rates (φ) was used to study non-isothermal thermal analysis, and also to gain more insight in to the Hruby index thermal stability, crystal growth index (n), glass forming tendency and so calorimetric characteristics of the present glasses. Also, the effects of the heating rate and MoO3 content on the glass transition temperature ( Tg) and crystallization temperature ( TCr) were studied. Further structural investigations were done by FESEM, EDX and Map. The glass transition temperature, glass transition region, the temperature corresponding to the onset of crystallization ( Tx) and also the crystallization temperature were obtained at different heating rates; heating rate dependence of these parameters was employed estimate the key kinetic parameters of glass transition and crystallization activation energy by using Moyinhan, Ozawa, Kissinger and Avrami methods. Calorimetric curves were used to plot the specific heat capacity curves versus temperature at the constant pressure. In addition, the compositional dependence of the heat capacity and fragility parameter were investigated. Generally, results of this work show that the glass with x = 20 mol% has the highest thermal stability and glass forming tendency and samples having 10 and 20% of MoO3 are the optimal samples (with the least fragility) for thermomechanical applications and also in optical fibers.