Variation of crystal habit with seeding temperature in case of DMSO

The overall variation of crystal habit with a change of seeding temperature is presented in Table 1. The observation is consistent with the fact that the principal factor governing the basic habit of ice crystal structure is temperature.28 Rogers and You29 have also concluded that the basic habits

Table 1. Crystal habits when DMSO is seeded. Temperature Crystal habit

— 22°C to —17°C Dominantly dendrite (Photo 1), some are hexagonal and cubic

[Dendrite (80.54%): 9.12-45.56jm; Hexagonal (10.16%): 4.25-25.12 jum; Cubic (9.3%): 5.13-11.24 jm]

— 17°C to —15°C Mostly cubic (Photo 2), some are hexagonal [Cubic (85.35%):

— 15°C to —7°C Mostly hexagonal (Photo 3), some are cubic or prism like

[Hexagonal (88.12%): 25.32-50 jm; Cubic or prism (11.88%): 10.25-45.32 um]

— 7° C to —0.5°C Almost all crystals are cubic or rod (Photo 4): (1.24-11.32 jm)

Photo 1. Dendrite formation at — 18.G0C.
Photo 2. Cubic crystals at — 16.G0 C.
Photo 3. Single hexagonal crystal at — 14.4°C.

of ice crystals are dependent on temperature, and they are independent of seeding materials.

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