Nucleation mechanisms: A crystal-chemical investigation of phases forming in highly supercooled aluminosilicate liquids
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| Title: | Nucleation mechanisms: A crystal-chemical investigation of phases forming in highly supercooled aluminosilicate liquids |
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| Authors: | Roskosz, Mathieu1 m.roskosz@gl.ciw.edu, Toplis, Michael J.1, Besson, Pascale2, Richet, Pascal3 |
| Source: | Journal of Non-Crystalline Solids. May2005, Vol. 351 Issue 14/15, p1266-1282. 17p. |
| Subjects: | Nucleation, Liquids, Spectrum analysis, Crystals, Ions |
| Abstract: | Abstract: Crystal nucleation and growth have been investigated approximately 100K above the glass transition for 12 liquids in the system CaO–Al2O3–SiO2. Nucleation takes place heterogeneously at the gas–liquid interface, yielding various crystal structures, namely, those of yoshiokaite, gehlenite, larnite, anorthite and wollastonite. Characterization by Raman spectroscopy, transmission electron microscopy and electron microprobe indicate that these phases are highly disordered, poorly crystallized and generally non-stoichiometric. Even for incongruent crystallization, crystals have the same Si/Al ratio as their parent melts but variable CaO contents. These features may be rationalized in terms of the contrasting mobility of network-forming cations, which practically vanishes at the glass transition, and that of calcium which remains significant. The fact that the mobility of network-modifying cations controls the structure and composition of nucleating phases implies that liquid viscosity (controlled by the mobility of network formers, i.e. the frequency of Si–O and Al–O bond breaking) is not an appropriate scaling parameter for crystal nucleation. In turn, this may provide an explanation for the discrepancies, reaching many orders of magnitude, between experimentally determined nucleation rates and those predicted from classical and non-classical nucleation theories. An additional factor contributing to such discrepancies is that thermodynamic data obtained on stoichiometric phases stable at liquidus temperatures are not appropriate for estimating the thermodynamic barrier to nucleation of the metastable crystals that actually form at large degrees of supercooling. [Copyright &y& Elsevier] |
| Copyright of Journal of Non-Crystalline Solids is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 17812849 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Nucleation mechanisms: A crystal-chemical investigation of phases forming in highly supercooled aluminosilicate liquids – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Roskosz%2C+Mathieu%22">Roskosz, Mathieu</searchLink><relatesTo>1</relatesTo><i> m.roskosz@gl.ciw.edu</i><br /><searchLink fieldCode="AR" term="%22Toplis%2C+Michael+J%2E%22">Toplis, Michael J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Besson%2C+Pascale%22">Besson, Pascale</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Richet%2C+Pascal%22">Richet, Pascal</searchLink><relatesTo>3</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Non-Crystalline+Solids%22">Journal of Non-Crystalline Solids</searchLink>. May2005, Vol. 351 Issue 14/15, p1266-1282. 17p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Nucleation%22">Nucleation</searchLink><br /><searchLink fieldCode="DE" term="%22Liquids%22">Liquids</searchLink><br /><searchLink fieldCode="DE" term="%22Spectrum+analysis%22">Spectrum analysis</searchLink><br /><searchLink fieldCode="DE" term="%22Crystals%22">Crystals</searchLink><br /><searchLink fieldCode="DE" term="%22Ions%22">Ions</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract: Crystal nucleation and growth have been investigated approximately 100K above the glass transition for 12 liquids in the system CaO–Al2O3–SiO2. Nucleation takes place heterogeneously at the gas–liquid interface, yielding various crystal structures, namely, those of yoshiokaite, gehlenite, larnite, anorthite and wollastonite. Characterization by Raman spectroscopy, transmission electron microscopy and electron microprobe indicate that these phases are highly disordered, poorly crystallized and generally non-stoichiometric. Even for incongruent crystallization, crystals have the same Si/Al ratio as their parent melts but variable CaO contents. These features may be rationalized in terms of the contrasting mobility of network-forming cations, which practically vanishes at the glass transition, and that of calcium which remains significant. The fact that the mobility of network-modifying cations controls the structure and composition of nucleating phases implies that liquid viscosity (controlled by the mobility of network formers, i.e. the frequency of Si–O and Al–O bond breaking) is not an appropriate scaling parameter for crystal nucleation. In turn, this may provide an explanation for the discrepancies, reaching many orders of magnitude, between experimentally determined nucleation rates and those predicted from classical and non-classical nucleation theories. An additional factor contributing to such discrepancies is that thermodynamic data obtained on stoichiometric phases stable at liquidus temperatures are not appropriate for estimating the thermodynamic barrier to nucleation of the metastable crystals that actually form at large degrees of supercooling. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Non-Crystalline Solids is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jnoncrysol.2005.02.021 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 17 StartPage: 1266 Subjects: – SubjectFull: Nucleation Type: general – SubjectFull: Liquids Type: general – SubjectFull: Spectrum analysis Type: general – SubjectFull: Crystals Type: general – SubjectFull: Ions Type: general Titles: – TitleFull: Nucleation mechanisms: A crystal-chemical investigation of phases forming in highly supercooled aluminosilicate liquids Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Roskosz, Mathieu – PersonEntity: Name: NameFull: Toplis, Michael J. – PersonEntity: Name: NameFull: Besson, Pascale – PersonEntity: Name: NameFull: Richet, Pascal IsPartOfRelationships: – BibEntity: Dates: – D: 15 M: 05 Text: May2005 Type: published Y: 2005 Identifiers: – Type: issn-print Value: 00223093 Numbering: – Type: volume Value: 351 – Type: issue Value: 14/15 Titles: – TitleFull: Journal of Non-Crystalline Solids Type: main |
| ResultId | 1 |
