抄録
In the previous paper it was made clear that potassium chloride crystallizes as single crystals of octahedral shape in the case of crystallization from potassium chloride solution which contains a small amount of the mixture of MnSO4and (NaPO3)n as addition. agent. In this paper the growth of the above octahedral crystal was studied by microscopic observation. Results obtained are as follows.
(1) When the supersaturation ratio of the above solution are from 1.04 to 1.06, concentric patterns appear on the surface of the growing crystal. When the ratio is under 1.03, irregular steps and hill rocks are observed. When the ratio is above 1.06, needle-like crystals deposit on the growing surface.
(2) Such a concentric pattern is considered to depend on the spiral growth because the center of the pattern resembles a spiral. But in many cases, hill rocks are found in the center.
(3) Applying Cabrera's theory, the value of the specific surface free energy calculated from data of the supersaturation, step spacing and step height of the pattern, seems too large compared with the value accepted generally.
