碲锌镉晶体晶格畸变的测定与分析

在高分辨X射线衍射仪上,利用不对称布拉格衍射STD技术与单晶摇摆曲线技术相结合的方法,对碲锌镉单晶材料的晶格畸变进行了分析测定。此方法实现了一次装样,多角度、多次测定晶体的摇摆曲线,从而利用多组实验数据完成多元线性回归方程组的求解,避开了一般应变测定方法中难以确定无应力状态下衍射角的问题。所测定的生长态碲锌镉晶片晶格畸变量为10-3~10-2数量级,该畸变量是碲锌镉晶片存在成份偏析、位错和空位等缺陷以及晶片受到的应力综合作用的结果。

Measurement and Analysis of Lattice Distortion of CdZnTe Single Crystal

A method based on X-ray analysis for the measurement of lattice distortion of single crystal was proposed.The asymmetrical Bragg reflection STD scan mode with the conventional X-ray diffraction rocking curve was used to determine the lattice distortion of CdZnTe single crystal in this method.Several rocking curves along different orientations were taken from the same sample during the experimental measurement.By using messages,from different X-ray rocking curves,multiple regression equations for calculating the strains were obtained without determining the diffraction angle in stress-free condition.The lattice distortion in an as-grown CdZnTe single crystal with heavy defects was determined to be 10~(-3)-10~(-2).It is suggested that the distortion is the sum of those introduced by three different reasons,i.e.compositional segregation,crystal defects,such as dislocations,Te precipitates,etc.,thermal and mechanical stresses.