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Publikace detail

The effect of powder coarseness on crystallization kinetics of Ge11Ga11Te78 infrared glass
Rok: 2017
Druh publikace: článek v odborném periodiku
Název zdroje: Journal of Thermal Analysis and Calorimetry
Název nakladatele: Springer
Místo vydání: Heidelberg
Strana od-do: 593-599
Tituly:
Jazyk Název Abstrakt Klíčová slova
cze Efekt zrnitosti prášku na krystalizační kinetiku Ge11Ga11Te78 infračerveného skla Efekt zrnitosti prášku na neizotermní krystalizační kinetiku Ge11Ga11Te78 skla byl studován metodou DSC. Multivariantní kinetická analýza byla použita k dekonvoluci získaných krystalizačních dat. Jednotlivé procesy byly identifikovány a popsány kinetickými modely. krystalizační kinetika; DSC; velikost částic; Ge11Ga11Te78 sklo; XRD
eng The effect of powder coarseness on crystallization kinetics of Ge11Ga11Te78 infrared glass The effect of powder particle size on non-isothermal crystallization kinetics of Ge11Ga11Te78 glass was examined by differential scanning calorimetry. Multivariate kinetic analysis was used to deconvolute the complex crystallization data. The overall process was found to be composed of initial tellurium precipitation followed by simultaneous formation of Ga2Te5 and GeTe phases. While the Te precipitation followed the nucleation growth Johnson-Mehl-Avrami kinetics with the growth originating mainly from surface and mechanically induced defects, the formation of gallium and germanium tellurides proceeded autocatalytically with a significantly lower involvement of the defects-based crystal growth. The model-based part of the kinetic behavior was found to be uninfluenced by the change in powder coarseness-both crystallization sub-processes were described in terms of similar models with similar kinetic exponents for all particle size fractions. On the other hand, the model-free kinetic parameters (activation energies, pre-exponential factors and crystallization enthalpies) were found to be significantly changing with increasing particle size; the observed trends were explained in terms of the changing amounts of the two involved types of crystallization centers. Crystallization kinetics; DSC; Particle size; Ge11Ga11Te78 glass; XRD