Combined Focused Ion Beam-Ultramicrotomy Method for TEM Specimen Preparation of Porous Fine-Grained Materials

Abstract

A new transmission electron microscopy (TEM) specimen preparation method that utilizes a combination of focused ion beam (FIB) methods and ultramicrotomy is demonstrated. This combined method retains the benefit of site-specific sampling by FIB but eliminates ion beam-induced damage except at specimen edges and allows recovery of many consecutive sections. It is best applied to porous and/or fine-grained materials that are amenable to ultramicrotomy but are located in bulk samples that are not. The method is ideal for unique samples from which every specimen is precious, and we demonstrate its utility on fine-grained material from the one-of-a-kind Paris meteorite. Compared with a specimen prepared by conventional FIB methods, the final sections are uniformly thin and free from re-deposition and curtaining artifacts common in FIB specimens prepared from porous, heterogeneous samples.

The Trends of In Situ Focused Ion Beam Technology: Toward Preparing Transmission Electron Microscopy Lamella and Devices at the Atomic Scale

“…Lee et al. [ 111–113 ] proposed a planar sample preparation technique based on “microcapsules” for a 2D material grown on a substrate. The microcapsule is mainly composed of the surrounding wall and the top cover ( Figure C).…”

“…Therefore, a reliable method is needed to prepare planar transmission electron microscope samples of 2D materialbased devices. Lee et al [111][112][113] proposed a planar sample preparation technique based on "microcap sules" for a 2D material grown on a substrate. The microcap sule is mainly composed of the surrounding wall and the top cover (Figure 8C).…”

Application of FIB-SEM Techniques for the Advanced Characterization of Earth and Planetary Materials

“…For ultrathinning of submicron particles on a surface, initial E-beam capping rather than the Ga + beam eliminates any possible sputtering of small particles on a surface [56]. Additionally, combining FIB with ultramicrotomy can overcome the challenges of some fine-grained samples, making them free from ion beam damage, redeposition, or curtaining [10,57].…”

Sample Preparation and Coordinated Analysis for Characterization of Organic Matter in Return Samples from the Carbonaceous Asteroids Ryugu and Bennu

“…Here, we describe a hybrid FIB-SEM + ultramicrotomy protocol to prepare sections for coordinated STXM/TEM analysis from a large (~350 µm) particle of crushed meteorite. This protocol is an improvement from previous approaches [2,3] because it provides serial sections while preserving asteroidal organic matter. We selected the JbiletWinselwan carbonaceous meteorite as an analog sample for its similar IR spectral signature and heating history to Ryugu [4,5].…”