The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses
The addition of small amounts of niobium or tantalum oxide to lithium disilicate glass provokes a drastic decrease of the steady-state nucleation rates and the crystal growth velocities. The viscosity of the residual glassy matrix is considered as a function of the crystallization degree in the cour...
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| Format: | Online |
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Nature Publishing Group
2016
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4858696/ |
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pubmed-48586962016-05-19 The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses Thieme, Katrin Avramov, Isak Rüssel, Christian Article The addition of small amounts of niobium or tantalum oxide to lithium disilicate glass provokes a drastic decrease of the steady-state nucleation rates and the crystal growth velocities. The viscosity of the residual glassy matrix is considered as a function of the crystallization degree in the course of a non-isothermal crystallization. For simplification, a homogeneous distribution of the added oxides in the glass matrix is assumed. While the viscosity initially decreases, it significantly increases again for higher crystallization degrees hindering crystal growth. However, it was shown that the additives are enriched at the crystal interface. Several possible reasons for the inhibition of nucleation and growth kinetics such as viscosity, interfacial energy crystal/glassy phase, thermodynamic driving force or impingement rate are discussed. Since the crystallization front is blocked by the additives the impingement rate is decreased with increasing additive concentration. Since small concentrations of Nb2O5 and Ta2O5 have a drastic effect on the nucleation, these components should be enriched at the interface crystal/glass. This will only take place, if it leads to a decrease in the interfacial energy. Since this effect alone should result in an increase of the nucleation rate, it must be overcompensated by kinetic effects. Nature Publishing Group 2016-05-06 /pmc/articles/PMC4858696/ /pubmed/27150844 http://dx.doi.org/10.1038/srep25451 Text en Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Thieme, Katrin Avramov, Isak Rüssel, Christian |
| spellingShingle |
Thieme, Katrin Avramov, Isak Rüssel, Christian The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| author_facet |
Thieme, Katrin Avramov, Isak Rüssel, Christian |
| author_sort |
Thieme, Katrin |
| title |
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| title_short |
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| title_full |
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| title_fullStr |
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| title_full_unstemmed |
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| title_sort |
mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses |
| description |
The addition of small amounts of niobium or tantalum oxide to lithium disilicate glass provokes a drastic decrease of the steady-state nucleation rates and the crystal growth velocities. The viscosity of the residual glassy matrix is considered as a function of the crystallization degree in the course of a non-isothermal crystallization. For simplification, a homogeneous distribution of the added oxides in the glass matrix is assumed. While the viscosity initially decreases, it significantly increases again for higher crystallization degrees hindering crystal growth. However, it was shown that the additives are enriched at the crystal interface. Several possible reasons for the inhibition of nucleation and growth kinetics such as viscosity, interfacial energy crystal/glassy phase, thermodynamic driving force or impingement rate are discussed. Since the crystallization front is blocked by the additives the impingement rate is decreased with increasing additive concentration. Since small concentrations of Nb2O5 and Ta2O5 have a drastic effect on the nucleation, these components should be enriched at the interface crystal/glass. This will only take place, if it leads to a decrease in the interfacial energy. Since this effect alone should result in an increase of the nucleation rate, it must be overcompensated by kinetic effects. |
| publisher |
Nature Publishing Group |
| publishDate |
2016 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4858696/ |
| _version_ |
1613576247057580032 |