Study on Heat and Mass Transport in Liquid during Faceted Cellular Array Growth

在半导体、氧化物超导体等晶体材料中，由于熔融而产生的熵变较大的材料，在推进的固/液界面上经常会观察到多面状的胞状结构。许多研究人员已经接受了在稳态生长时保持这种多面形态的机制，即溶质堆积和随后的细胞界面底部的过冷。然而，Higashino、Intom i和Kuribayashi(HIK)报告说，使用光学干涉仪，在透明有机化合物的刻面界面之前出现了一个重新卷曲的区域。在本研究中，利用干涉可视化技术和传统的微热电偶测温技术，对推进界面前方的温度分布进行了精确测量。结果表明，潜热对界面前方温度分布的影响与潜热释放率和扩散通量所定义的无量纲参数定性相关。此外，由于温度分布的变化，刻面界面的形态不稳定性也被归结为。

In materials whose entropy change due to fusion are large, such as semiconductor, oxide superconductor and other crystalline materials, faceted cellular morphology is often observed on the advancing solid/liquid interface. The mechanism to maintain this faceted morphology at steady-state growth had been accepted by many researchers to be solute pile-up and subsequent undercooling at the bottom of the cellular interface. Higashino, Inatomi and Kuribayashi (HIK), however, reported the appearance of a recalesced region ahead of the faceted interface in transparent organic compounds, using an optical interferometer. In the present study, precise measurement of the temperature distribution ahead of the advancing interface was carried out by means of an interferometric visualization technique as well as a conventional temperature measurement technique using microthermocouples. The result is that the influence of latent heat on the temperature distribution ahead of the interface was correlated qualitatively with a nondimensional parameter defined by the release rate and the diffusion flux of latent heat. In addition, morphological instabilities of the faceted interface were attributed to the change in the temperature distribution.