Nanoporous materials are a large group of materials with a wide range of applications such as gas storage and separation, catalysis, sensors or electrochemical energy conversion and storage [1]. Understanding the fundamental mechanisms of diffusion and adsorption of atomic and molecular species within the pores of this class of materials is, therefore, of paramount importance. While the localization of single atoms in crystalline materials has already been demonstrated using high resolution TEM based techniques [2], the high susceptibility of most nanoporous specimen to the electron beam imposes significant challenges for quantitative high-resolution investigations of such materials [3].

Here we present our results on the quantitative analysis of single atoms adsorbed within the channels of beryl (Be₂AlSi₆O₁₈). By statistical analysis of the atomic column intensities and comparison with series of multislice simulations we are able to determine the local thickness of the specimen, as well as the three-dimensional position of single adsorbed Cs atoms within the channels, based on a single STEM high-angle annular dark-field (HAADF) image. Extracting all needed information from a single high-resolution micrograph, allows us to reduce beam damage effects to a minimum, which is a promising methodology also for the analysis of other porous materials.

References

[1] S. Polarz; B. Smarsly; Journal of Nanoscience and Nanotechnology, 2002, 2, 6, 581.

[2] Z. Chen et al.; Science, 2021, 372, 6544, 826.

[3] J. Fatermans et al.; Nanoscale, 2022, 14, 26, 9323.