TWINNING AND THE TABULAR GROWTH OF SILVER BROMIDE CRYSTALS
TWINNING AND THE TABULAR GROWTH OF SILVER BROMIDE CRYSTALS
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DOI：
10.1038/180293a0
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发表时间：
1957-01-01
期刊：
影响因子：
64.8
通讯作者：
HERZ, RH
中科院分区：
文献类型：
--
作者：
BERRIMAN, RW;HERZ, RH
溴化银具有氯化钠型结构，因此在均匀环境中生长的完美晶体不会显示出任何不对称生长的趋势。事实上，银在明胶中的分散体，例如在照相乳剂中，可以获得由规则多面体组成的分散体（图1），这表明可以获得均匀的生长环境。然而，在生长期间的相同环境中，但具有不同的成核条件，可以获得分散体，其中晶体是扁平的，扁平面具有三角形或六边形形状（图2）。它可以表明，在相同的环境条件下，在三维的规则多面体晶体的均匀生长进行得比“向外”的片状晶体的生长慢得多，也就是说，片状生长是由于平行于片状面的增强生长，而不是抑制生长在这些面。
SILVER bromide has the sodium chloride-type structure, so that a perfect crystal, growing in a uniform environment, would not be expected to show any tendency to unsymmetrical growth. The fact that dispersions of silver bromide in gelatin, for example in photographic emulsions, can be obtained which do consist of regular polyhedra (Fig. 1) shows that a uniform environment for growth can be obtained. In the same environment during growth, but with different conditions of nucleation, however, dispersions can be obtained in which the crystals are tabular, the tabular faces having triangular or hexagonal shapes (Fig. 2). It can be shown that under identical environmental conditions, the uniform growth in three dimensions of the regular polyhedral crystals proceeds much more slowly than the ‘outward’ growth of the tabular crystals, that is, the tabular growth is due to enhanced growth parallel to the tabular faces rather than to repression of growth on these faces.