硫脲硫酸锌晶体(100)面台阶生长动力学实时研究

In situ study of the kinetics of growth steps on (100) faces of zinc(tris) thiourea sulphate crystal

运用光学显微镜实时观测了硫脲硫酸锌晶体(100)面台阶推移过程。获得了不同过饱和度、不同台阶高度、不同生长时间、不同台阶边缘扭折密度下的台阶推移速率;应用"净流量"模型解释了不同台阶推移速率的差异与过饱和度之间的依赖关系,计算了生长单元与台阶融合活化能及单台阶的动力学系数。通过分析发现台阶推移速率随过饱和度增加而线性增加,随台阶高度增加而下降;同一台阶推移速率随时间变化的现象与台阶重组过程有关;而台阶边缘扭折密度则从根本上决定了台阶推移速率的大小和变化趋势。

In-situ observation of movement process of steps on the（100） face of ZTS crystal in aqueous solutions was performed by using optical microscopy.The displacement velocities under different conditions of predefined supersaturation,actual steps height,growth durations,and densities of kinks on the steps edge were obtained.The dependence of the rate difference between various steps on the supersaturation was explained by the ＂net flux model＂.The values of activation energy for integration of growth unit in a step and kinetic coefficient for a unit-hight step were calculated.Results show that the average displacement rate of steps increases linearly with an increase in supersaturation,and the velocity of steps decreases with an increase in their height.The change of the step displacement rate with growth duration is related to the processes of reorganisation of step.Meanwhile the value and changing trend of step displacement rate are primarily determined by the density of kinks on step edge.