Structural relaxation and viscosity of Al2O3 doped magnesium phosphate glasses

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F20%3A39916660" target="_blank" >RIV/00216275:25310/20:39916660 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S002230932030435X?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S002230932030435X?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnoncrysol.2020.120323" target="_blank" >10.1016/j.jnoncrysol.2020.120323</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Structural relaxation and viscosity of Al2O3 doped magnesium phosphate glasses

Popis výsledku v původním jazyce

Thermomechanical analysis and differential scanning calorimetry were used to study the viscosity and relaxation behavior of the Al2O3-doped magnesium phosphate glasses. Viscosity in the range (10(7) - 10(11)) Pa center dot s was described by the nowadays top performing multiparametric models. A fixed extrapolation of high-temperature viscosity according to the Eyring theory was applied with the exception of the Arrhenius equation. The activation energies of viscous flow were very close to the activation energy of enthalpy relaxation determined in terms of the Tool-Narayanaswamy-Moynihan model. On the contrary, the activation energy of volume relaxation was found to be much lower in comparison with the viscous flow activation energy. In general, the increase of the Al2O3 content leads to the increases of the viscosity, of the activation energies of viscous flow and structural relaxation (as well as of the kinetic fragilities calculated from these quantities), and of the temperatures characterizing the glass transition during the viscosity, volume, and enthalpy measurements. The phosphate chains interconnecting effect of the Al3+ ions was found to be much stronger than the influence of the MgO modifying oxide. However, the enthalpy changes during the relaxation processes seem to be primarily influenced by the MgO/P2O5 ratio. Consistence of the compositional interpretation of the obtained results indicates the benefits of the utilization of the correlation coefficients for attributing the structural units responsible for the changes of physico-chemical quantities.

Název v anglickém jazyce

Structural relaxation and viscosity of Al2O3 doped magnesium phosphate glasses

Popis výsledku anglicky

Thermomechanical analysis and differential scanning calorimetry were used to study the viscosity and relaxation behavior of the Al2O3-doped magnesium phosphate glasses. Viscosity in the range (10(7) - 10(11)) Pa center dot s was described by the nowadays top performing multiparametric models. A fixed extrapolation of high-temperature viscosity according to the Eyring theory was applied with the exception of the Arrhenius equation. The activation energies of viscous flow were very close to the activation energy of enthalpy relaxation determined in terms of the Tool-Narayanaswamy-Moynihan model. On the contrary, the activation energy of volume relaxation was found to be much lower in comparison with the viscous flow activation energy. In general, the increase of the Al2O3 content leads to the increases of the viscosity, of the activation energies of viscous flow and structural relaxation (as well as of the kinetic fragilities calculated from these quantities), and of the temperatures characterizing the glass transition during the viscosity, volume, and enthalpy measurements. The phosphate chains interconnecting effect of the Al3+ ions was found to be much stronger than the influence of the MgO modifying oxide. However, the enthalpy changes during the relaxation processes seem to be primarily influenced by the MgO/P2O5 ratio. Consistence of the compositional interpretation of the obtained results indicates the benefits of the utilization of the correlation coefficients for attributing the structural units responsible for the changes of physico-chemical quantities.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Non-Crystalline Solids

ISSN

0022-3093

e-ISSN

—

Svazek periodika

550

Číslo periodika v rámci svazku

December

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

"120323-1"-"120323-8"

Kód UT WoS článku

000589930700003

EID výsledku v databázi Scopus

2-s2.0-85089351098