title: Crystal Growth Kinetics and Viscous Behavior in Ge2Sb2Se5 Undercooled Melt.
abstract: Crystal growth, viscosity, and melting were studied in Ge2Sb2Se5 bulk samples. The crystals formed a compact layer on the surface of the sample and then continued to grow from the surface to the central part of the sample. The formed crystalline layer grew linearly with time, which suggests that the crystal growth is controlled by liquid-crystal interface kinetics. Combining the growth data with the measured viscosities and melting data, crystal growth could be described on the basis of standard crystal growth models. The screw dislocation growth model seems to be operative in describing the temperature dependence of the crystal growth rate in the studied material in a wide temperature range. A detailed discussion on the relation between the kinetic coefficient of crystal growth and viscosity (ukin ∝ η(-ξ)) is presented. The activation energy of crystal growth was found to be higher than the activation energy of crystallization obtained from differential scanning calorimetry, which covers the whole nucleation-growth process. This difference is considered and explained under the experimental conditions.
authors.affiliation: Department of Physical Chemistry, University of Pardubice , Studentská 573, Pardubice 532 10, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Barták
authors.affiliation: Department of Inorganic Technology, University of Pardubice , Doubravice 41, Pardubice 532 10, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Koštál
authors.affiliation: Department of Physical Chemistry, University of Pardubice , Studentská 573, Pardubice 532 10, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Podzemná
authors.affiliation: Department of Physical Chemistry, University of Pardubice , Studentská 573, Pardubice 532 10, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Shánělová
authors.affiliation: Department of Physical Chemistry, University of Pardubice , Studentská 573, Pardubice 532 10, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Málek