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

我们知道，在熔点以下的温度下，覆盖有准液态层的晶体表面比裸露的表面更稳定。这种现象是一种一级相变，我们称之为表面熔化。另一方面，类似的现象也可能发生在晶体与基体的界面处或晶体的晶界处。虽然人们对这一现象进行了理论研究，并通过宏观动力学等方法进行了模拟，但还没有直接的实验证据。本文用椭圆偏振法研究了冰晶-玻璃界面和冰13 EA晶体晶界处的熔化转变，并讨论了熔化转变的物理性质。实验结果表明：1）实验方法是椭圆偏振法，它是一种测量冰晶-玻璃界面和冰13 EA晶体晶界处熔化转变的光学方法; 2）测量冰晶-玻璃界面处熔化转变的光学方法; 3）测量冰晶-玻璃界面处熔化转变的光学方法; 4）测量冰晶-玻璃界面处熔化转变的光学方法; 5）测量冰晶-玻璃界面处熔化转变的光学方法; 6）测量冰晶-玻璃界面处熔化转变的光学方法; 7）测量冰晶-玻璃界面处熔化转变的光学方法; 8）测量冰晶-玻璃界面处熔化转变的光学方法; 9）测量冰晶-玻璃界面处熔化转变的光学方法; 13）测量冰晶-玻璃界面处熔化转变的光学方法; ...更多信息 计算了界面处薄层的厚度和光学常数。本文介绍了一种新的椭偏仪，用于测量冰玻璃界面过渡层的厚度和折射率。2）在-1 ℃以上的温度范围内，在冰-玻璃界面处发现了一个过渡层，其厚度随温度的升高而急剧增加，其折射率与水的折射率非常接近。这一结果表明，在冰-玻璃界面处的过渡层应该是准液态层，在该界面处可以发生熔化转变。3）发展了一种新的测量冰晶晶界处过渡层厚度和光学常数的椭圆偏振法。用一种特殊的方法制备了冰晶样品，如用人工籽晶从过冷水中生长出冰晶体。4）用新的椭偏仪观察了冰晶晶界处的过渡层。5）讨论了冰晶-玻璃界面和冰晶晶界处的熔化转变的物理性质。这一结果将发表在1991年的《晶体生长杂志》上。少

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