Atomic-resolution electron energy loss spectroscopy imaging in aberration corrected scanning transmission electron microscopy

Phys Rev Lett. 2003 Sep 5;91(10):105503. doi: 10.1103/PhysRevLett.91.105503. Epub 2003 Sep 5.

Abstract

The "delocalization" of inelastic scattering is an important issue for the ultimate spatial resolution of innershell spectroscopy in the electron microscope. It is demonstrated in a nonlocal model for electron energy loss spectroscopy (EELS) that delocalization of scanning transmission electron microscopy (STEM) images for single, isolated atoms is primarily determined by the width of the probe, even for light atoms. We present experimental data and theoretical simulations for Ti L-shell EELS in a [100] SrTiO3 crystal showing that, in this case, delocalization is not significantly increased by dynamical propagation. Issues relating to the use of aberration correctors in the STEM geometry are discussed.