Abstract
The purpose of this research was to investigate the control of crystal orientation of ice by using a capillary filled with supercooling water. We used two types of capillaries: straight and triangular-wave bended, both of which were made of stainless steel and had 0.4 millimeter in outer diameter. It was found that ice crystals of various orientations grew in the straight capillaries, and at the end of the capillary, c-axes of the crystals were perpendicular to the capillary. Then, using the triangular-wave bended capillaries, about 60 percent of crystals at 0.6 K of supercooling had perpendicular c-axes to a plane containing the bended capillary. Observing crystals before and after the bended section, it was shown that whether the c-axis of the crystal after the section was controlled or not depended on the c-axis of the crystal before the section. Additionally, growth velocities of ices growing in the bended capillaries were measured. All of the crystals growing relatively quickly had perpendicular c-axes to the plane containing the bended capillary. From the results, we proposed the improvements of the system to increase probability of c-axis control.
