Study of the melting transition at the interface of ice crystal using an ellipsometry

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It is known that the crystal surface coverd with the quasi-liquid layr is more stable than the naked surface at temperatures just below the melting point. This phenomenon is a kind of first-order phase transition and specially called the surface me13EA\ : lting. On the other hand, the similar phenomena may occur at the interface between crystal and substrate or at the grain boundary of crystals. Though these phenomena have been studied theoretically and simulated by the morecular dynamics method and so on, any direct evidence by the experimental methods has not been reported. The purpose of this scientific research is to detect the melting transition at both the interface between ice crystal and glass substrate and at the grain boundary of ice13EA\ : crystals by the method of ellipsometry, and discuss the physical properties of the melting transition.The results are summarized as follows,1) The experimental method used in this research is an ellipsometry which is an optical method to m … More easure both the thickness and the optical constant of the thin layr at the interface. A new ellipsometer was constructed to measure the thickness and13EA\ : the refractive index of the transition layr at the ice-glass interface between. Total accuracy of the measurement is in 10A for the thickness and about 0.01 for the refractive index of transition layr.2) A transition layr was detected at the ice-glass interface in the temperature reagion above-1ﾟC.The thickness of the transition layr steeply increased with increasing temperature and the refractive index of the layr was vely close to the refra13EA\ : ctive index of bulk water. This result means that the transition layr at the ice-glass interface should be quasi-liquid layr and the melting transition can occur at the this interface.3) A new method of ellipsometry was developed to measure the thickness and the optical constant of the transition layr at the grain boundary of ice crystals. Used samples of ice crystals was prepared by a special method such as the ice by crystals was grown from the supercooled water using an artificial seed crystal.4) Using the new ellipsometer, we were able to observe the transition layr at the grain boundary.5) We discussed the physical properties of the melting transition of at the ice-glass interface and the grain boundary of ice crystals. This result will be published in the Journal of Crystal Growth in 1991. Less