Activity: Talk or presentation › Invited talk › Science to science
Description
Electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDXS) in the scanning transmission electron microscope (STEM) are powerful methods for elemental mapping at the nano- and atomic scale. In addition, EELS also provides information about chemical bonding or about optical materials properties. Usually, a TEM only gives projected 2D information about a sample, but by acquisition and reconstruction of a tomographic tilt series STEM imaging and spectroscopy can be extended to the third spatial dimension. In this presentation, I will introduce the principles of spectroscopic STEM imaging for accessing elemental information, but also for the excitation and imaging of surface polariton fields stemming from either plasmons or optical phonons. I will show examples of surface plasmon imaging on different plasmonic materials and devices, ranging from single metallic nanoparticles to more complex multimaterial assemblies. Finally, I will discuss the combination of spectroscopy and tomography for accessing elemental composition in three dimensions, as well as for reconstruction the electromagnetic properties of surface polariton fields.