Gliko Olga, Reviakine Ilya, Vekilov Peter G
Department of Chemical Engineering, University of Houston, Houston, Texas 77204, USA.
Phys Rev Lett. 2003 Jun 6;90(22):225503. doi: 10.1103/PhysRevLett.90.225503.
Bunching of growth steps plagues layerwise crystallization of materials in laboratory, industrial, and geological environments, and theory predicts that equidistant step trains are unstable under a variety of conditions. Searching for an example of stable equidistant step trains, we monitored the generation and spatiotemporal evolution of step trains on length scales from 100 nm to 1 mm during the crystallization of insulin, using atomic force microscopy and phase-shifting interferometry. We show that near-equidistant step trains are generated by single and cooperating screw dislocation. The lack of step-step interaction and the overall transport-controlled growth regime further regularize the step train and ensure the stability of the obtained equidistant arrangement.
生长台阶的聚集困扰着材料在实验室、工业和地质环境中的层状结晶，并且理论预测等距台阶列在各种条件下都是不稳定的。为了寻找稳定等距台阶列的例子，我们在胰岛素结晶过程中，使用原子力显微镜和相移干涉测量法，在100纳米至1毫米的长度尺度上监测了台阶列的产生和时空演化。我们表明，近等距台阶列是由单个和协同的螺旋位错产生的。台阶间相互作用的缺乏以及整体的输运控制生长机制进一步使台阶列规则化，并确保了所获得的等距排列的稳定性。
