Zeolites have unique porous atomic structures and are useful as catalysts, ion exchangers, and molecular sieves. It is challenging to directly observe the local atomic structures of the material via electron microscopy due to low electron irradiation resistance. As a result, the fundamental property-structure relationships of the constructs remain unclear.
Recent developments of a low-electron dose imaging method known as optimum bright-field scanning transmission electron microscopy (OBF STEM) offer a method to reconstruct images with a high signal-to-noise ratio with high dose efficiency.
In this study, Kousuke Ooe and a team of scientists in engineering and nanoscience at the University of Tokyo and the Japan Fine Ceramics Center performed low-dose atomic resolution observations with the method to visualize atomic sites and their frameworks between two types of zeolites. The scientists observed the complex atomic structure of the twin-boundaries in a faujasite-type (FAU) zeolite to facilitate the characterization of local atomic structures across many electron beam-sensitive materials.
Zeolites are porous materials that are regularly arranged in nanosized pores suited for a variety of applications during catalysis, gas separation, and ion exchange. The material properties are closely related to the pore geometry allowing subsequent interactions with adsorbed guest molecules and ions. Researchers have thus far used diffractometric methods to analyze the structure of zeolites.
For example, materials scientists have demonstrated scanning electron microscopy to be a powerful method to analyze local structures to observe the atomic arrangement of electron-resistant materials at the sub-angstrom level. Zeolites are, however, more electron-beam sensitive when compared to other organic materials, thereby limiting electron microscopy-based observations due to electron irradiation.
2023-08-14 14:48:03
Source from phys.org
