Direct Determination of Dislocation Sense of Closed-Core Threading Screw Dislocations using Synchrotron White Beam X-ray Topography in 4H Silicon Carbide
Direct Determination of Dislocation Sense of Closed-Core Threading Screw Dislocations using Synchrotron White Beam X-ray Topography in 4H Silicon Carbide
复制标题
使用 4H 碳化硅中同步加速器白束 X 射线形貌直接测定闭芯螺纹螺位错的位错方向
DOI：
10.1063/1.2793705
复制
发表时间：
2007
影响因子：
4
通讯作者：
M. Dudley
中科院分区：
文献类型：
--
作者：
Yi Chen;M. Dudley
掠入射同步加速器白色束X射线形貌图像的闭芯螺纹螺旋位错在4H碳化硅出现大致椭圆形的白色功能，与暗对比度的不对称周长，这是大大增强的一侧或另一侧的g矢量。光线追踪模拟表明，增强的暗对比度特征的相对位置揭示了闭芯螺旋位错的意义。位错的意义，从而获得验证使用背反射图像记录与小布拉格角。因此，无论是掠入射或“小布拉格角”背反射同步加速器白色束X射线形貌术，可以明确地揭示闭芯螺纹螺位错的意义。
Grazing-incidence synchrotron white beam x-ray topography images of closed-core threading screw dislocations in 4H silicon carbide appear as roughly elliptically shaped white features, with an asymmetric perimeter of dark contrast which is greatly enhanced on one side or other of the g vector. Ray-tracing simulations indicate that the relative position of the enhanced dark contrast feature reveals the sense of the closed-core screw dislocation. Dislocation senses so obtained were validated using back-reflection images recorded with small Bragg angle. Therefore, the sense of the closed-core threading screw dislocations can be unambiguously revealed using either grazing-incidence or “small Bragg angle” back-reflection synchrotron white beam x-ray topography.