Nucleation and Crystallization

Differential Thermal Analysis was used to calculate the heterogeneous nucleation rates for lithium disilicate glass doped with different concentrations of platinum particles.  The lithium disilicate glass was melted with 0.001 and 0.005 wt% platinum and with PtCl4 for the investigation, and compared with the same glass un-doped. Heterogeneous volume nucleation was observed and the number of nuclei as a function of time was calculated for temperatures 440°C, 450°C, and 470°C. Results indicated a higher magnitude of heterogeneous nucleation rate for the glass doped with platinum compared to glass doped with PtCl4. Highest nucleation rate was at 455˚C with 6.5 ´1011 m-3s-1 for the glass doped with 0.005wt% platinum particles while nucleation rate for glass doped with 0.001wt%PtCl4 was 9.5 ´ 108 m-3s-1. Results calculated by differential thermal analysis are in good agreement to those estimated by the optical microscopy and molecular simulation measurements.

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Heterogeneous crystallization on platinum particle on lithium disilicate glass(LS2) Glass.

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Nucleation Rate Curves with doped and un-doped glass

 

 

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