Crystal growth kinetics in cordierite and diopside glasses in wide temperature ranges
- We measured and collected literature data for the crystal growth rate, u(T), of µ-cordierite (2MgO · 2Al2O3 · 5SiO2) and diopside (CaO · MgO · 2SiO2) in their isochemical glass forming melts. The data cover exceptionally wide temperature ranges, i.e. 8001350 °C for cordierite and 7501378 °C for diopside. The maximum of u(T) occurs at about 1250 °C for both systems. A smooth shoulder is observed around 970 °C for µ-cordierite. Based on measured and collected viscosity data, we fitted u(T) using standard crystal growth models. For diopside, the experimental u(T) fits well to the 2D surface nucleation model and also to the screw dislocation growth mechanism. However, the screw dislocation model yields parameters of more significant physical meaning. For cordierite, these two models also describe the experimental growth rates. However, the best fittings of u(T) including the observed shoulder, were attained for a combined mechanism, assuming that the melt/crystal interface growing fromWe measured and collected literature data for the crystal growth rate, u(T), of µ-cordierite (2MgO · 2Al2O3 · 5SiO2) and diopside (CaO · MgO · 2SiO2) in their isochemical glass forming melts. The data cover exceptionally wide temperature ranges, i.e. 8001350 °C for cordierite and 7501378 °C for diopside. The maximum of u(T) occurs at about 1250 °C for both systems. A smooth shoulder is observed around 970 °C for µ-cordierite. Based on measured and collected viscosity data, we fitted u(T) using standard crystal growth models. For diopside, the experimental u(T) fits well to the 2D surface nucleation model and also to the screw dislocation growth mechanism. However, the screw dislocation model yields parameters of more significant physical meaning. For cordierite, these two models also describe the experimental growth rates. However, the best fittings of u(T) including the observed shoulder, were attained for a combined mechanism, assuming that the melt/crystal interface growing from screw dislocations is additionally roughened by superimposed 2D surface nucleation at large undercoolings, starting at a temperature around the shoulder. The good fittings indicate that viscosity can be used to assess the transport mechanism that determines crystal growth in these two systems, from the melting point Tm down to about Tg, with no sign of a breakdown of the StokesEinstein/Eyring equation.…
Autor*innen: | Stefan ReinschORCiD, M.L.F. Nascimento, Ralf Müller, E. D. Zanotto |
---|---|
Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Journal of non-crystalline solids |
Jahr der Erstveröffentlichung: | 2008 |
Verlag: | North-Holland Publ. Co. |
Verlagsort: | Amsterdam |
Jahrgang/Band: | 354 |
Ausgabe/Heft: | 52-54 |
Erste Seite: | 5386 |
Letzte Seite: | 5394 |
Freie Schlagwörter: | Crystal growth; Kinetik; Kristallwachstumsgeschwindigkeit; Oxide glasses; Silicates; Silikatgläser |
DOI: | 10.1016/j.jnoncrysol.2008.09.007 |
ISSN: | 0022-3093 |
Verfügbarkeit des Dokuments: | Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access") |
Bibliotheksstandort: | Sonderstandort: Publica-Schrank |
Datum der Freischaltung: | 19.02.2016 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 25.11.2008 |