Focused ion beam scanning electron microscopy in soil science: new approaches to soil structure analysis

Abstract

This paper examines the use of focused ion beam imaging combined with scanning electron microscopy (FIB-SEM) to study the submicron structure of soil aggregates. The study focused on migratory-micellar chernozem soil from the Central Chernozem Reserve. A comparative analysis was conducted between images obtained using FIB-SEM and X-ray computed tomography. The primary objective of the study was to determine whether FIB-SEM studies could complement those using computed tomography alone. FIB-SEM demonstrated the ability to detect pores with a radius of less than 1 μm, which are inaccessible to tomography, and to identify organic inclusions and specific pore morphotypes (crack-like, elongated, and jagged), reflecting physicochemical processes at the nanoscale. However, the limited field of view and the high complexity of segmentation reduce the representativeness of the method. The obtained results confirm the applicability of FIB-SEM as a supplement to traditional tomography in the study of soil nanostructure, opening up prospects for the analysis of the spatial organization of organic matter and clarification of the mechanisms of structure formation at the submicron level.

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