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Correlation between the activation energies of structural relaxation and viscous flow for BaO-P2O5-Al2O3 glasses
Autoři: Svoboda Roman | Chromcikova Maria | Hruska Branislav | Liska Marek
Rok: 2020
Druh publikace: článek v odborném periodiku
Název zdroje: Journal of Non-Crystalline Solids
Název nakladatele: Elsevier Science BV
Místo vydání: Amsterdam
Strana od-do: "119998-1"-"119998-10"
Tituly:
Jazyk Název Abstrakt Klíčová slova
cze Korelace mezi aktivační energií strukturní relaxace a viskózního toku pro BaO-P2O5-Al2O3 skla Viskozita a strukturní relaxace byly studovány pomocí TMA pro 6 vybraných skel systému BaO-P2O5-Al2O3. Z naměřených dat byly získány aktivační energie a vzájemně porovnány. aktivační energie; viskozita; strukturní relaxace; TMA; BaO-P2O5-Al2O3 skla
eng Correlation between the activation energies of structural relaxation and viscous flow for BaO-P2O5-Al2O3 glasses Viscosity and structural relaxation were studied by thermomechanical analysis for six Al2O3 -doped BaO-P2O5 glasses. The low-temperature viscosity data (10(7) - 10(11) Pa.s) were described and modeled by the Vogel-Fulcher-Tammann, Avramov-Milchev and Mauro-Yue-Ellison-Gupta-Allan equations. Temperature dependence of the activation energy of viscous flow was determined from the tangent of the extrapolated (in terms of the three viscosity equations) viscosity-temperature data-curves. Values of the activation energy of viscous flow were compared to the activation energies of volume relaxation determined from the exact physico-chemical description of the cyclic thermomechanical measurements performed over the glass transition region. In addition, differential scanning calorimetry was used to determine the activation energies of enthalpy relaxation. Good correspondence between the relaxation and viscosity activation energies was found in the respective temperature ranges. Good agreement was also confirmed for the viscosity and enthalpy fragilities, as well as for the indicator of the thermodynamic fragility. Activation energy; Viscosity; Structural relaxation; TMA; BaO-P2O5-Al2O3 glasses