Atomic force microscopy measurement of ice crystal's melting and growing in AFP III solution
This sequence of frames was taken at a fixed position while changing the temperature of the cold finger. The time from the first until the last frames were recorded is 6 hours. The time intervals between the frames are not uniform and vary between an hour to 4 minutes. The temperature of the cold finger is initially elevated from -2.70 ℃ to -2.55 ℃ in steps of 0.05 ℃, causing partial melting of the ice crystal and the disappearance of the crystal structure. During this fine melting, the macroscopic crystal shape does not change since the z position of the cantilever changes from 90 to 80 µm above the mica. Then, the temperature of the cold finger is lowered. The lowering of the temperature induces ice growth and the appearance of partially faceted cone structures. Between the cones, there are partially facetted pits. During this cooling, the temperature is lowered from -2.55 ℃ to -3.10 ℃ by 0.03-0.10 ℃ step ranges (temperatures of the scans are indicated in the movie). During the ice growth, the z position of the cantilever changes from 80 to 85 µm above the mica, indicating that the ice grows only microscopically during this cooling sequence.