Löffler Stefan, Stöger-Pollach Michael, Steiger-Thirsfeld Andreas, Hetaba Walid, Schattschneider Peter
University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria.
Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany.
Materials (Basel). 2021 Mar 9;14(5):1314. doi: 10.3390/ma14051314.
Energy-loss magnetic chiral dichroism (EMCD) is a versatile method for measuring magnetism down to the atomic scale in transmission electron microscopy (TEM). As the magnetic signal is encoded in the phase of the electron wave, any process distorting this characteristic phase is detrimental for EMCD. For example, elastic scattering gives rise to a complex thickness dependence of the signal. Since the details of elastic scattering depend on the electron's energy, EMCD strongly depends on the acceleration voltage. Here, we quantitatively investigate this dependence in detail, using a combination of theory, numerical simulations, and experimental data. Our formulas enable scientists to optimize the acceleration voltage when performing EMCD experiments.
能量损失磁圆二色性（EMCD）是一种在透射电子显微镜（TEM）中测量低至原子尺度磁性的通用方法。由于磁信号编码在电子波的相位中，任何扭曲这一特征相位的过程都会对EMCD产生不利影响。例如，弹性散射会导致信号出现复杂的厚度依赖性。由于弹性散射的细节取决于电子的能量，EMCD强烈依赖于加速电压。在此，我们结合理论、数值模拟和实验数据，对这种依赖性进行了详细的定量研究。我们的公式使科学家在进行EMCD实验时能够优化加速电压。
