• 文献标题:   Lattice contrast in the core-loss EFTEM signal of graphene
  • 文献类型:   Article
  • 作  者:   MOHN MJ, BISKUPEK J, LEE Z, ROSE H, KAISER U
  • 作者关键词:   energyfiltered transmission electron microscopy, highresolution transmission electron microscopy, atomicresolution imaging, preservation of elastic contrast, mutual coherence function, twodimensional material
  • 出版物名称:   ULTRAMICROSCOPY
  • ISSN:   0304-3991 EI 1879-2723
  • 通讯作者地址:   Univ Ulm
  • 被引频次:   0
  • DOI:   10.1016/j.ultramic.2020.113119
  • 出版年:   2020

▎ 摘  要

The realization of chromatic aberration correction enables energy-filtered transmission electron microscopy (EFTEM) at atomic resolution even for large energy windows. Previous works have demonstrated lattice contrast from ionization-edge signals such as the L-2,L-3 edges of silicon or titanium. However, the direct interpretation as chemical information was found to be hampered by contributions from elastic contrast with dynamic scattering, especially for thick samples. Here we demonstrate that even for thin samples with light atoms, the interpretation of the ionization-edge signal is complicated by inversions from bright-atom to dark-atom contrast. Our EFTEM experiments for graphene show lattice contrast in the carbon K-edge signal, and we find bright-atom and dark atom contrast for different defoci.