Studies on Whisker of Ice Crystals

冰晶晶须的研究

• 批准号: 60460229
• 负责人: KURODA Toshio
• 金额: $ 4.16万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60460229/
• 关键词: Whisker; Ice crystal; Kinetic coefficient; Condensation coefficient; Screw dislocation; らせん転位; スパイラル成長; 氷

Purpose of this study is to investigate an origin of ice whisker and a mechanism of growth of its tip surface ((0001)). The following results were obtained.1) We made an experimental apparatus for growth of ice whisker from the vapor phase at -80゜C at lowest and for in-situ observation of grawing whisker using a refrigerator LAUDA-SK80D which was bought by this Grant.2) We succeded in growing ice whisker on (0001)substrate of PBI_2 crystal at -50[[ -70゜C. Its growth direction is c-axis and tip surface is composed of (0001) face.3) Since a probablity of growth of ice whisker was less than 1%, a necessary condition of ice whisker growth is that screw dislocations intersect only (0001) faces of ice crystals nucleated on PbI_2 substrate.4) The Growth rates R_<exp> of tip surface were measured as functions of supersaturation<sigma>_<<infinite>> 5) The experimental results were analyzed by taking into account the diffusion process of water molecules and the surface kinetic process for incorporating the molecules into crystal lattice, and it was found that the dependences on surface supersaturation of kinetic coefficient and condensation coefficient were interpreted by spiral growth with the aid of screw dislocations.

本研究的目的是研究冰晶须的起源及其尖端表面的生长机制（(0001)）。得到了以下结果：1)我们制作了一个实验装置，用于在最低-80℃的气相中生长冰晶须，并使用本基金购买的LAUDA-SK80D冰箱对生长的晶须进行现场观察。2)我们成功地在-50[-70 C的PBI_2晶体（0001）衬底上生长了冰晶须。其生长方向为c轴，尖端表面由（0001）面组成。3)由于晶须生长的概率小于1%，因此晶须生长的必要条件是螺旋位错只与PbI_2衬底上成核的冰晶（0001）面相交。4)测量了尖端表面的生长速率R_<exp>作为过饱和< σ >_<<infinite>>的函数。5)考虑了水分子的扩散过程和分子溶入晶格的表面动力学过程，对实验结果进行了分析，发现动力学系数和冷凝系数对表面过饱和的依赖关系可以用螺旋位错辅助螺旋生长来解释。

项目成果

T.Kobayashi: Journal of Crystal Growth.

T.Kobayashi：晶体生长杂志。

Toshio Kuroda: Journal of Crystal Growth.

黑田敏夫：晶体生长杂志。

Toshio,Kuroda: "Growth Mechanism of Ice Whisker" Journal of Crystal Growth.

Toshio，Kuroda：“冰晶须的生长机制”晶体生长杂志。