Nion UltraSTEM Applications
Imaging and Plasmonics
Here, STEM-EELS is used to probe plasmonic behavior of a gold nanostar. The highly localized electron probe matches localized excitations with two energies -- 670 and 1360 meV. The small probe imaging, in addition, provides evidence that the two modes are parallel and perpendicular polarizations of individual nanostar arms. T. Tsoulos et al. Colloidal plasmonic nanostar antennas with wide range resonance tunability. Nanoscale 11 (2019) 18662
Subnanometer resolution thermometry
High energy resolution (~9 meV) permits vibrational spectroscopy. By probing both energy gain and loss regions and applying the Principle of Detailed Balance, EELS provides not only the vibrational signature but also the temperature information of the sample under study at the subnanometer scale. M Lagos and P. Batson. Thermometry with Subnanometer Resolution in the Electron Microscope Using the Principle of Detailed Balancing. Nano Lett. 18 (2018) 4556
Imaging vacancy defects in 2D Materials
Annular dark field image of a single-layer MoS2 showing different types of defects: single sulfur vacancy (orange circles) and double sulfur vacancy (yellow circle). The intensity line profiles along lines L1 – L3 demonstrating the defect profiles. Higher contrast is obtained from the Mo atoms compared to one S atom (~30% of the Mo intensity) and two S atoms (~45% of the Mo intensity). D Voiry et al. The Role of Electronic Coupling Between Substrate and 2D MoS2 Nanosheets in Electrocatalytic Production of Hydrogen. Nat. Mater. 15 (2016) 1003
Imaging and EELS of single atoms in carbon peapod structure
A series of dark field (A-C) and bright field (D) images of a single-wall carbon nanotube stuffed with C82 nanopods. Each nanopod initially contained one erbium atom, and these heavy atoms are imaged as bright dots. C and Er are identified by EELS. Source: http://nion.com/results.html Sample courtesy of K. Suenaga.
