- 著者
-
黒田 登志雄
Lacmann Rolf
- 出版者
- 日本結晶成長学会
- 雑誌
- 日本結晶成長学会誌 (ISSN:03856275)
- 巻号頁・発行日
- vol.6, no.3, pp.51-64, 1979-12-25
The new interpretation on habits ofice growing from vapour is proposed. The primary habits of ice alternate three times (plates→ - 4℃→ columns → -10℃ → plates→from -20℃ to -35℃ → columns) with decreasing temperature. The theory is based on a viewpoint that the surface of ice just below 0℃ is covered with a quasi liquid layer, whose depth or coverage 〓 decreases with falling temperature, and therefore the growth mechanism of a surface changes also as followings : i) Vapour-Quasi Liquid-Solid-Mechanism (〓>1) , ii) Adhesive Growth on a surface strongly adsorbed by water molecules (0.01<〓<1) and iii) Two Dimensional Nucleation Growth on a singular surface (〓<0.01) . As the change in surface structure as well as growth mechanism depend on surface orientation, the complicated habits change is caused mainly by the combination of growth mechanism of each surface, i.e. {0001} and {101^^-0 }. The first and second transition temperature are expected to be independent on absolute supersaturation Δp as same as experiments. On the other hand the third one is the temperature where the two dimensional nucleation growth of {0001} surface reaches the one of { 101^^-0}, so that it falls with decreasing Δp. The observed marked columnar crystals can be explained only by {0001} account of spherical volume diffusion field near taking surfaces and cylindrical one near {1010} surfaces. For plate like crystals between - 10℃ and -20℃ to -35℃ the surface diffusion from {0001} to {101^^-0} and volume diffusion with cylindrical symmetry near {101^^-0} surfaces are very important.