用AFM观测凝胶法下KClO4晶体的生长机理

用原子力显微镜(atomic force microscopy,AFM)对凝胶法生长的KClO4晶体的最重要面{001}面微观形貌进行了研究。结果表明,在不同的过饱和度下,KClO4晶体分别表现为二维成核生长、三维成核生长、层核生长以及多层堆垛生长等生长机理。从热力学角度解释了过饱和度对KClO4晶体生长机理的影响。对二维成核生长机理,揭示了KClO4晶体生长中二维核的形状和取向,及生长台阶的取向。研究结果还表明,杂质的存在将阻止台阶的向前推进,并导致聚并台阶及弯曲台阶的形成。

An atomic force microscopy study of the growth mechanism of a potassium perchlorate single crystal grown using the gel method

Atomic force microscopy was employed to study the microtopography on the {001} surface of potassium perchlorate single crystals obtained by the gel method.This surface plays an important role on the growth of potassium perchlorate single crystals.The results show that the potassium perchlorate single crystals display various growth mechanisms at different supersaturations,including the two-dimensional nucleation growth mechanism,three-dimensional nucleation growth mechanism,layer-nucleation growth mechanism and stack growth mechanism.The effects of supersaturations on the growth mechanisms could be understood from a thermodynamic viewpoint.The shape and orientation of the twodimensional nuclei and the orientation of growth steps were observed.The results demonstrate that the impurities in the growth system display negative effects on the single crystal growth.