Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-587230
Surface Crystallization of Barium Fresnoite Glass: Annealing Atmosphere, Crystal Morphology and Orientation
- Controlled oriented crystallization of glass surfaces is desired for high precision applications, since the uppermost crystal layer significantly influences the properties of the material. In contrast to previous studies, the data presented here deal with separated crystals growing at defect-free surfaces in four atmospheres with different degrees of humidity (ambient/dry air, argon and vacuum). A glass with the composition 2 BaO–TiO2–2.75 SiO2 was heat-treated at 825 °C until fresnoite (Ba2TiSi2O8) grew to a significant size. The crystal growth rate is found to increase with increasing humidity. The morphology of the crystals changes from highly distorted dendrites in the driest atmosphere (vacuum) to circular/spear-head-shaped crystals in the wettest atmosphere (ambient air), which we attribute to a decrease in viscosity of the glass surface due to water uptake. The least distorted crystals appear in the form of depressions of up to 6 µm. This has an influence on the observed crystalControlled oriented crystallization of glass surfaces is desired for high precision applications, since the uppermost crystal layer significantly influences the properties of the material. In contrast to previous studies, the data presented here deal with separated crystals growing at defect-free surfaces in four atmospheres with different degrees of humidity (ambient/dry air, argon and vacuum). A glass with the composition 2 BaO–TiO2–2.75 SiO2 was heat-treated at 825 °C until fresnoite (Ba2TiSi2O8) grew to a significant size. The crystal growth rate is found to increase with increasing humidity. The morphology of the crystals changes from highly distorted dendrites in the driest atmosphere (vacuum) to circular/spear-head-shaped crystals in the wettest atmosphere (ambient air), which we attribute to a decrease in viscosity of the glass surface due to water uptake. The least distorted crystals appear in the form of depressions of up to 6 µm. This has an influence on the observed crystal orientation, as measured by electron backscatter diffraction (EBSD). The pulled-in crystals change the orientation during growth relative to the flat glass surface due to an enrichment in SiO2 at the crystal fronts. This confirms that the orientation of crystals is not fixed following nucleation.…
Autor*innen: | Franziska Scheffler, Mirjam Fleck, Richard BuschORCiD, Santiago CasadoORCiD, Enrico GneccoORCiD, Christopher Tielemann, Delia S. Brauer, Ralf Müller |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Crystals |
Jahr der Erstveröffentlichung: | 2023 |
Organisationseinheit der BAM: | 5 Werkstofftechnik |
5 Werkstofftechnik / 5.6 Glas | |
Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
Verlag: | MDPI AG |
Verlagsort: | Basel |
Jahrgang/Band: | 13 |
Ausgabe/Heft: | 3 |
Aufsatznummer: | 475 |
Erste Seite: | 1 |
Letzte Seite: | 17 |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Crystal growth; Crystal morphology; Crystal orientation; EBSD; Fresnoite; Surface crystallization |
Themenfelder/Aktivitätsfelder der BAM: | Material |
DOI: | 10.3390/cryst13030475 |
URN: | urn:nbn:de:kobv:b43-587230 |
Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
Lizenz (Deutsch): | Creative Commons - CC BY - Namensnennung 4.0 International |
Datum der Freischaltung: | 02.11.2023 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 02.11.2023 |
Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |