Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses
Introducing an interaction parameter γ, we implement modifier interaction and the mixed-alkali effect into bond constraint theory, and apply this extension for simplistic property prediction on ternary phosphate glasses. The severity of the mixed alkali effect results from the interplay of two simul...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2016-05-01
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| Series: | Frontiers in Materials |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmats.2016.00025/full |
| _version_ | 1828431986941755392 |
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| author | Bruno ePoletto Rodrigues Joachim eDeubener Lothar eWondraczek |
| author_facet | Bruno ePoletto Rodrigues Joachim eDeubener Lothar eWondraczek |
| author_sort | Bruno ePoletto Rodrigues |
| collection | DOAJ |
| description | Introducing an interaction parameter γ, we implement modifier interaction and the mixed-alkali effect into bond constraint theory, and apply this extension for simplistic property prediction on ternary phosphate glasses. The severity of the mixed alkali effect results from the interplay of two simultaneous contributions: Bond constraints on the modifier species soften or stiffen with decreasing or increasing γ, respectively. When the modifier size is not too dissimilar the decrease in γ reflects that the alkali ions can easily migrate between different sites, forcing the network to continuously re-accommodate for any subsequent distortions. With increasing size difference, migration becomes increasingly difficult without considerable network deformation. This holds even for smaller ions, where the sluggish dynamics of the larger constituent result in blocking of the fast ion movement, leading to the subsequent increase in γ. Beyond a certain size difference in the modifier pair, a value of γ exceeding unity may indicate the presence of steric hindrance due to the large surrounding modifiers impeding the phosphate network to re-accommodate deformation. |
| first_indexed | 2024-12-10T18:12:50Z |
| format | Article |
| id | doaj.art-84877e82a42e4f45accbc1c6479d603f |
| institution | Directory Open Access Journal |
| issn | 2296-8016 |
| language | English |
| last_indexed | 2024-12-10T18:12:50Z |
| publishDate | 2016-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Materials |
| spelling | doaj.art-84877e82a42e4f45accbc1c6479d603f2022-12-22T01:38:24ZengFrontiers Media S.A.Frontiers in Materials2296-80162016-05-01310.3389/fmats.2016.00025198331Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glassesBruno ePoletto Rodrigues0Joachim eDeubener1Lothar eWondraczek2Otto-Schott-Institute of Materials ResearchClausthal University of TechnologyOtto-Schott-Institute of Materials ResearchIntroducing an interaction parameter γ, we implement modifier interaction and the mixed-alkali effect into bond constraint theory, and apply this extension for simplistic property prediction on ternary phosphate glasses. The severity of the mixed alkali effect results from the interplay of two simultaneous contributions: Bond constraints on the modifier species soften or stiffen with decreasing or increasing γ, respectively. When the modifier size is not too dissimilar the decrease in γ reflects that the alkali ions can easily migrate between different sites, forcing the network to continuously re-accommodate for any subsequent distortions. With increasing size difference, migration becomes increasingly difficult without considerable network deformation. This holds even for smaller ions, where the sluggish dynamics of the larger constituent result in blocking of the fast ion movement, leading to the subsequent increase in γ. Beyond a certain size difference in the modifier pair, a value of γ exceeding unity may indicate the presence of steric hindrance due to the large surrounding modifiers impeding the phosphate network to re-accommodate deformation.http://journal.frontiersin.org/Journal/10.3389/fmats.2016.00025/fullglass transition temperaturetopological constraintsPhosphate glassesMixed alkali effectBond constraint theory |
| spellingShingle | Bruno ePoletto Rodrigues Joachim eDeubener Lothar eWondraczek Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses Frontiers in Materials glass transition temperature topological constraints Phosphate glasses Mixed alkali effect Bond constraint theory |
| title | Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| title_full | Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| title_fullStr | Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| title_full_unstemmed | Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| title_short | Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| title_sort | modifier interaction and mixed alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses |
| topic | glass transition temperature topological constraints Phosphate glasses Mixed alkali effect Bond constraint theory |
| url | http://journal.frontiersin.org/Journal/10.3389/fmats.2016.00025/full |
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