Extend Materials Science into the next dimension
katana microtome is a new compact and user-friendly volume electron microscopy (vEM) system that has been developed for use in scanning electron microscopes (SEM). katana microtome is used to perform serial block-face scanning electron microscopy (SFB-SEM), a method that has already established itself as a critical tool in biological and medical research, driving advancements in these fields. Though commonly used in life sciences to generate highly detailed 3D images of tissues and organisms, the application of SBF-SEM in materials science and metallurgy remains significantly less explored due to challenges with sectioning these samples.
Here, we showcase the successful use of katana microtome for SBF-SEM in materials science, achieving high-resolution 3D visualisations of both battery cathode material and aluminium. The extension of SBF-SEM with katana microtome into materials science offers the opportunity to enable further understanding in areas such as corrosion behaviour of metals, the impact of organic coatings on corrosion, pigment distributions in paints and the dispersion of intermetallic grains, in the same way as that has been achieved in the life sciences.
Fig 1. Katana microtome mounted on a JEOL 7800 stage
NMC Battery Material (LiNiMnCo2)
Lithium Nickel Manganese Cobalt Oxide Cathode for Li-ion Batteries
Over the last decade, significant attention has been given to lithium-ion battery research due to both its wide application in consumer electronics, transport electrification and power grid storage, as well as the critical role it will play in sustainability. While much progress has been made, current lithium-ion technology will not be suitable in the long term to meet the increasing demand for better battery performance required by society. Over time, batteries will require both longer lifespan and better power and energy storage performance. To achieve this, a comprehensive and detailed understanding of the structures and chemistry of each component of the lithium-ion battery will be necessary. Scanning electron microscopy is a crucial imaging and analysis technique used for the characterisation of the microstructure of these battery materials. However, current SEM techniques only allow two-dimensional quantitative characterisation and cannot truly be extended to provide an accurate representation of the 3D microstructure.
Employing katana microtome for SBF-SEM of these materials provides a powerful tool which enables researchers to acquire high-resolution volume data resulting in accurate microstructures at the nanometre scale. This can be used, for example, to investigate distributions of agglomerates, micro-grains or particle crack formation as a result of charge/discharge cycling. Figure 2 shows an example dataset of a Ni-Mn-Co cathode material sample which has been acquired using SBF-SEM with katana microtome.
Fig. 2 (A) Single slice image taken from a Ni-Co-Mn sample on an aluminium substrate showing the distribution of larger particles throughout the material. (B) Volumetric dataset of the Ni-Co-Mn sample. Original data was 5120x3840 images, 306 serial slices, 12nm pixels and acquired using katana microtome installed on a JEOL IT700HR FEG SEM.
Aerospace, Automotive and other Machine Manufacturing
Aluminium and other metal alloys continue to play a critical role in aerospace, automotive, shipbuilding and various other machine manufacturing fields due to their mechanical behaviour, excellent castability, high strength-to-weight ratios and resistance to corrosion. Traditionally, most structural research has relied on two-dimensional imaging obtained by conventional methods such as 2D SEM. However, for quantitative characterisation of size, shape, connectivity and distribution of pores, grains and intermetallic compounds also requires data in the vertical (z-axis) direction. Some researchers have attempted to make quantitative assessments of 3D information using several 2D images, but as with the battery materials discussed above, this approach doesn’t truly yield an accurate and representative spatial microstructure. Therefore, using katana microtome for SBF-SEM enables researchers to acquire high-resolution volume data of metal alloy samples, resulting in detailed 3D spatial microstructures and accurate characterisations and distributions of those properties mentioned above.
With katana microtome, users can acquire not only 3D volume SEM data, but the system also allows for simultaneous EDX measurement leading to highly detailed elemental analysis throughout the volume. Figure 3 shows an example volume dataset of aluminium (AL6061) obtained via simultaneous SBFSEM and EDX using katana microtome revealing the different elemental inclusions throughout the sample.
Fig 3. (A) Image of a single slice taken from a volumetric dataset of an aluminium alloy. (B) EDX element map acquired with an Oxford Instruments Ultim Extreme detector of the same image obtained simultaneously to the SEM image. (C) Volumetric EDX dataset showing the distribution of inclusions throughout the sample volume. The original data was acquired on a Tescan S8000 SEM.