Two types of quasi-liquid layers on ice crystal surfaces observed by atomic force microscopy

2015 Fiscal Year Final Research Report

• Project/Area Number: 25870009
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Crystal engineering; Thin film/Surface and interfacial physical properties
• Research Institution: Hokkaido University
• Principal Investigator: Nagashima Ken 北海道大学, 低温科学研究所, 助教 (60436079)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 氷 / 疑似液体層 / 結晶成長 / 原子間力顕微鏡 / 干渉計

Outline of Final Research Achievements

I improved Atomic Force Microscope (AFM) for observation of ice crystal surfaces. I controlled ambient temperature and humidity by using commercial incubator and homemade observation cell by using Peltier elements with water-cooled system. Then I succeeded in scanning single ice crystals by using AFM.
However, we newly found that Quasi-Liquid Layers (QLLs) on ice crystal surfaces do not appear under equilibrium environment because QLLs are deposited from supersaturated water vapor. The most important point of AFM observation of ice crystals is suppression of vertically moving of ice surfaces. Therefore, it was difficult that QLLs were stably observed by AFM under saturated water vapor pressure. Instead of using AFM, we could estimate the thicknesses of two types of QLLs by interferometer and wetting theory. In addition, we found that QLLs are stable under equilibrium environment in the presence of hydrogen chloride gas and QLLs under such environment would be observed by AFM.

Free Research Field

結晶成長