In specimens with an inhomogeneous displacement field in electron beam direction dynamical diffraction effects lead to complex non-linear properties of the diffracted electron wave. Consequently, the diffracted beam's phase contains information about the inhomogeneous displacement field. These phases are experimentally and theoretically investigated under different excitation errors and specimen thicknesses as well as for different depths of the displacement field. An inclined InGaAs layer with a larger lattice constant than the surrounding GaAs matrix serves as controlled displacement field, which is inhomogeneous in electron beam direction with a continuously changing depth. The phase and amplitude of the diffracted beam are measured by dark-field electron holography. The measurements agree with calculations performed by numerical propagation of the electron wave using the Darwin-Howie-Whelan equations. A strong dependency on the excitation conditions is found showing that the interplay between dynamical effects and the strain field must be considered in the interpretation of the geometric phase.

中文翻译：

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非均匀应变场几何相位的动力学衍射效应

在电子束方向上具有不均匀位移场的样品中，动态衍射效应导致衍射电子波的复杂非线性特性。因此，衍射光束的相位包含有关非均匀位移场的信息。在不同的激发误差和试样厚度以及位移场的不同深度下，对这些相进行了实验和理论研究。晶格常数大于周围 GaAs 矩阵的倾斜 InGaAs 层用作受控位移场，其在电子束方向上不均匀，深度连续变化。衍射光束的相位和幅度由暗场电子全息术测量。测量结果与使用 Darwin-Howie-Whelan 方程通过电子波的数值传播进行的计算一致。发现对激发条件有很强的依赖性，这表明在解释几何相位时必须考虑动力学效应和应变场之间的相互作用。