• Gspan, Christian
• Hofer, Ferdinand
• Kothleitner, Gerald
• Grogger, Werner
• Mitsche, Stefan
• Simic, Nikola
• Knez, Daniel

Abstract

Nanoporous materials constitute a diverse group with numerous applications, including gas<br/>storage and separation, catalysis, sensors, and electrochemical energy conversion and<br/>storage [1]. Understanding the fundamental mechanisms of diffusion and adsorption of<br/>atomic and molecular species within the pores of this class of materials is, therefore,<br/>paramount. While the localization of single atoms in crystalline materials has been<br/>demonstrated using high resolution TEM based techniques [2], the high susceptibility of most<br/>nanoporous specimen to the electron beam presents significant challenges for quantitative<br/>high-resolution investigations of these materials [3]. Here, we present our results on the<br/>quantitative analysis of single atoms adsorbed within the channels of beryl (Be2AlSi6O18).<br/>Through statistical analysis of the atomic column intensities and comparison with multiple<br/>series of multislice simulations, we determine the local thickness of the specimen, as well as<br/>the three-dimensional position of single adsorbed Cs atoms within the channels, based on a<br/>single STEM high-angle annular dark-field (HAADF) image. Extracting all necessary<br/>information from a single highresolution micrograph, enables us to minimize beam damage effects, offering a promising methodology also for the analysis of other porous<br/>materials [4].

Topics

• porous
• impedance spectroscopy
• pore
• simulation
• transmission electron microscopy
• susceptibility
• quantitative determination method