QDev Seminar: Jun Yamasaki

Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Japan

A new imaging method in TEM based on electron diffractive imaging

In diffractive imaging, a localized sample structure is reconstructed from its Fraunhofer diffraction pattern through iterative calculations. Although this novel imaging method has been extensively studied by coherent X-rays, electron diffractive imaging (EDI) is more suitable for analyses of nanometer-sized materials because of strong interactions between electrons and atoms. One of the advantages of EDI is visualization capability of phases in transmission electron waves after passing through samples. In this “Diffractive Phase Imaging”, a selected-area diffraction pattern and the corresponding bright-field TEM image are measured as amplitude information in reciprocal and real spaces, respectively. Since the complex wave fields in the both spaces are connected by Fourier transform, the amplitude information act as constrains to estimate the phase information lost in the TEM image. Some application results will be shown in the talk.