Login for students

Login for employees

Publication detail

How nucleation-growth kinetics is influenced by initial degree of material crystallinity
Year: 2016
Type of publication: článek v odborném periodiku
Name of source: Thermochimica Acta
Publisher name: Elsevier Science BV
Place: Amsterdam
Page from-to: 28-35
Titles:
Language Name Abstract Keywords
cze Jaký vliv má počáteční stupeň krystalinity na nukleačně růstovou kinetiku Vliv částečné krystalinity na neizotermní krystalizační nukleačně růstovou kinetiku byl zkoumán pomocí metody DSC na vybraných sklech systému Se-Te. Z výsledků je patrné, že aktivační energie ani krystalizační mechanismu nejsou ovlivněny počátečním stupněm krystalinity vzorku v případě krystalizace z mechanicky indukovaných defektů. naopak v případě komplexního krystalizačního chování již dochází k výraznému ovlivnění krystalizačního procesu. krystalizační kinetika; JMA model; DSC; stupeň krystalinity
eng How nucleation-growth kinetics is influenced by initial degree of material crystallinity Differential scanning calorimetry was used to investigate the effect of initial partial crystallinity on the non-isothermal nucleation-growth Johnson-Mehl-Avrami kinetics - selected Se-Te chalcogenide glasses were used as model systems. Different reproducible degrees of initial crystallinity were achieved by non-isothermal heating to a selected temperature. In case of the materials that primarily crystallize from mechanically induced defects, no change of the activation energy or kinetic mechanism was observed with increasing degree of initial crystallinity. On the other hand, material that showed complex crystallization behavior consisting from two competing overlapping crystal growth processes originating from volume-located nuclei and mechanical defects, respectively, exhibited marked shift in the dominance between the two kinetic mechanisms. In particular, with the increasing degree of initial crystallinity the defects-based crystallization mechanism started to dominate over the classical classic-nucleation-theory-based nucleation-growth crystallization mechanism. Increased amount of defects-based crystallization centers formed during the primary pre-crystallization appears to be the key factor for this change of the kinetic mechanism, rather than decreased activation energy (associated with the already existing crystal/glass interface) accelerating the actual crystal growth micro-mechanism. Crystallization kinetics; JMA model; DSC; Partial crystallinity

Departments

Other Parts

Map

en.mapy.cz

Services

Popular Links

© 2023 University of Pardubice, Studentská 95, 532 10 Pardubice 2
Phone: +420 466 036 111, 466 036 112, 466 036 113
Webmaster, RSS
Data box ID: f5vj9hu
Accessibility Statement
CC BY-NC-ND 4.0Creative CommonsAttributionNonCommercialNoDerivatives