Thermal analysis of Al droplet crystallization and modeling of the nucleation process: how to interpret experimental data?

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F21%3A00545284" target="_blank" >RIV/68378271:_____/21:00545284 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Thermal analysis of Al droplet crystallization and modeling of the nucleation process: how to interpret experimental data?

Popis výsledku v původním jazyce

The crystallization of Aluminum (Al) droplet was detected by the Differential Scanning Calorimetry (DSC) at the temperature Tc = 642 C (undercooling 18 K) using broad range of cooling rates 2-20 K/min. In the next step, the repeated DSC measurements at the isothermal conditions with undercooling of ca. 6 K discovered that the crystallization event occured after relatively long time delay 10-50 min. Experimental data confirmed the stochastic nature of crystal nucleation similarly to other systems. We analyzed the DSC data using the Johnson-Mehl-Avrami (JMA) model and also via numerical solution of the standard kinetic model of nucleation. In this case, the JMA model fails as the dimensionality of the growth is unrealistic. The crystallization probably occurs by a two-step mechanism, i.e. when the structure of small sub-critical clusters differs from the larger ones and thus the nucleation kinetics is slow.n

Název v anglickém jazyce

Thermal analysis of Al droplet crystallization and modeling of the nucleation process: how to interpret experimental data?

Popis výsledku anglicky

The crystallization of Aluminum (Al) droplet was detected by the Differential Scanning Calorimetry (DSC) at the temperature Tc = 642 C (undercooling 18 K) using broad range of cooling rates 2-20 K/min. In the next step, the repeated DSC measurements at the isothermal conditions with undercooling of ca. 6 K discovered that the crystallization event occured after relatively long time delay 10-50 min. Experimental data confirmed the stochastic nature of crystal nucleation similarly to other systems. We analyzed the DSC data using the Johnson-Mehl-Avrami (JMA) model and also via numerical solution of the standard kinetic model of nucleation. In this case, the JMA model fails as the dimensionality of the growth is unrealistic. The crystallization probably occurs by a two-step mechanism, i.e. when the structure of small sub-critical clusters differs from the larger ones and thus the nucleation kinetics is slow.n

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/EF16_019%2F0000760" target="_blank" >EF16_019/0000760: Fyzika pevných látek pro 21. století</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů