AFM investigation of step kinetics and hillock morphology of the {100} face of KDP
AFM investigation of step kinetics and hillock morphology of the {100} face of KDP
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DOI：
10.1016/j.jcrysgro.2003.08.054
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发表时间：
2004-01-09
影响因子：
1.8
通讯作者：
DeYoreo, JJ
中科院分区：
文献类型：
--
作者：
Thomas, TN;Land, TA;DeYoreo, JJ
在0 < sigma < 0.15的过饱和度范围内测量了KDP {100}面上的阶跃速度和小丘斜率，其中sigma是过饱和度。宏观台阶的形成及其随距丘顶距离的变化规律也被观察到。丘体坡度与过饱和度和丘体几何形状呈线性关系。这两个不相等的部门表现出不同的斜率和步进速度。AFM示出了3.7埃的基本台阶高度，或单位单元高度的一半，而先前的干涉测量实验假设基本台阶是单位单元。台阶边缘能量（α）、慢和快方向的动力学系数（β（S）和β（F））以及慢和快台阶运动的活化能（E-a、E-S和E-a、E-F）的值分别计算为24.0 erg/cm（2）、0.071 cm/s、0.206 cm/s、0.26 eV/分子和0.21 eV/分子。宏步骤，包括对时间的台阶高度和梯田宽度的距离的依赖性的演变进行了分析，并与已发表的模型的预测进行了比较。结果不允许我们区分冲击波模型和连续阶跃倍增模型。后一模型中的分析导致杂质的特征吸附时间为0.0716 s。(C)2003 Elsevier B. V.保留所有权利。
Step velocities and hillock slopes on the {100} face of KDP were measured over a supersaturation range of 0 < sigma < 0.15, where sigma is the supersaturation. The formation of macrosteps and their evolution with distance from the hillock top were also observed. Hillock slope depended linearly on supersaturation and hillock geometry. The two non-equivalent sectors exhibited different slopes and step velocities. AFM shows an elementary step height of 3.7 Angstrom, or half the unit cell height, whereas previous interferometric experiments assumed the elementary step was a unit cell. Values of the step edge energy (alpha), the kinetic coefficients for the slow and fast directions (beta(S) and beta(F)), and the activation energies for slow and fast step motion (E-a,E-S and E-a,E-F) were calculated to be 24.0 erg/cm(2), 0.071 cm/s, 0.206 cm/s, 0.26 eV/molecule, and 0.21 eV/molecule, respectively. Analysis of macrostep, evolution including the dependence of step height on time and terrace width on distance were performed and compared to predictions of published models. The results do not allow us to distinguish between a shock wave model and a continuous step-doubling model. Analysis within the latter model leads to a characteristic adsorption time for impurities of 0.0716 s. (C) 2003 Elsevier B.V. All rights reserved.