Sponsored by TescanReviewed by Ify IsiborNov 13 2026
Atom probe tomography (APT) facilitates three-dimensional compositional characterization at the quasi-atomic scale. This technique sees widespread use in the study of semiconductors, metals, and alloys, and more recently, natural and battery materials.
APT was initially conceived in the 1950s with the development of the field ion microscope (FIM) by Erwin Müller and colleagues. Contemporary atom probes are commercially distributed by Cameca and are designed around the local electrode.1
The company’s most recent developments include advances in electrostatic lens design and the use of deep-UV laser pulsing, enabling an ultra-wide field of view suitable for exploring novel materials over unprecedented volumes.2
The preparation of the extremely sharp needle-shaped specimens required for APT has been achieved by many methods over the years.3
APT specimens with an initial tip radius of ∼100 nm and a half-shank angle of ∼10 ° are generally desirable. It is also important that any region of interest (ROI) be located within the first 100 to 200 nm below the sample’s apex.
Focused ion beam-scanning electron microscopes (FIB-SEMs) have recently simplified the sample preparation process using gallium (Ga) ions. This approach regularly enables the preparation of more sparsely distributed ROIs and new materials.
The milling accuracy of Ga FIB-SEMs is excellent, but their limited beam current range may require many hours to prepare a suitably large batch of APT samples. APT is a destructive characterization method, meaning that it may require several attempts to capture a desired ROI.
The emergence of the Xe (xenon) plasma PFIB-SEM over the last decade has enabled faster material removal rates. This is attributed to the higher atomic mass of Xe ions and the availability of a much wider range of ion beam currents.
A further benefit of Xe PFIBs is that inert Xe minimizes ion-beam-induced contamination, which is key to ensuring reliable composition mapping with APT.
PFIBs are also less likely to induce amorphization for a wide range of materials, versus Ga FIBs.4 PFIBs generally represent a superior alternative to Ga FIBs in terms of high-throughput processing and sample integrity, but PFIBs cannot match Ga FIBs’ resolution.
This issue was mitigated by the launch of the AMBER X 2 PFIB in August 2024, featuring Tescan’s advanced Mistral Xe PFIB column.
This new column design offers a distinct beam profile optimization, resulting in an ion beam geometry able to rival the geometry of Ga FIBs. This system, therefore, offers the benefits of a PFIB while being able to compete with the resolution offered by Ga FIBs.
A new application note from Tescan demonstrates that it is possible to accurately characterize both multiphase high-entropy alloys and additively manufactured AlCuCeZr alloys using the Tescan AMBER X 2 at Sydney Microscopy and Microanalysis.
References
- Larson, D.W., et al. (2013). Local Electrode Atom Probe Tomography: A User’s Guide. New York, NY: Springer New York. DOI: 10.1007/978-1-4614-8721-0. https://link.springer.com/book/10.1007/978-1-4614-8721-0.
- Tegg, L., et al. (2023). Characterising the performance of an ultrawide field-of-view 3D atom probe. Ultramicroscopy, 253, p.113826. DOI: 10.1016/j.ultramic.2023.113826. https://www.sciencedirect.com/science/article/pii/S0304399123001432?via%3Dihub.
- Gault, B., et al. (2012). Atom Probe Microscopy. Springer Series in Materials Science. New York, NY: Springer New York. DOI: 10.1007/978-1-4614-3436-8. https://link.springer.com/book/10.1007/978-1-4614-3436-8.
- Zhong, X., et al. (2020). Comparing Xe+pFIB and Ga+FIB for TEM sample preparation of Al alloys: Minimising FIB-induced artefacts. Journal of Microscopy, 282(2), pp.101–112. DOI: 10.1111/jmi.12983. https://onlinelibrary.wiley.com/doi/10.1111/jmi.12983.
This information has been sourced, reviewed, and adapted from materials provided by Tescan Group.
For more information on this source, please visit Tescan Group.