Sample Preparation & Focused Ion Beam
No Experiment without a Specimen
Specimen preparation is a critical step in successful transmission electron microscopy (TEM) investigations. The quality of the experimental data that can be obtained from TEM studies is highly dependent on the quality of the specimen. If the specimen quality is not sufficient, e.g. if the specimen does not have the correct thickness for the intended experiment or is damaged during the preparation process, TEM investigations become very challenging or even impossible. With this in mind, the mission and focus of the Specimen Preparation Group is to support and enable TEM-based research by providing specimens of the highest possible quality and tailored to experimental needs for a wide variety of materials, devices, and geometries.
This includes continuous evaluation of specimen quality, investigation and understanding of damage and degradation mechanisms, continuous improvement of existing preparation routes, and development of new recipes for evolving experimental setups such as in-situ TEM or 4D STEM.
Due to the increasing complexity of sample materials and the miniaturization of modern devices, the preparation of TEM specimens often has to be very precise. Dual-beam microscopes, e.g. FIB-SEM systems, are indispensable for this purpose because they allow site-specific and orientation-specific structuring and processing that would not be possible with conventional preparation methods.
References:
C. Xiao, H. Wang, R. Usiskin, P. A. van Aken, and J. Maier
Unification of insertion and supercapacitive storage concepts: Storage profiles in titania,
Science 386(6720), 407-413 (2024).
https://doi.org/10.1126/science.adi5700
H. Wang, J. Zhang, C. Shen, C. Yang, K. Küster, J. Deuschle, U. Starke, H. Zhang, M. Isobe, D. Huang, P. A. van Aken, and H. Takagi
Direct visualization of stacking-selective self-intercalation in epitaxial Nb1+xSe2 films,
Nat. Commun. 15, 2541 (2024).
https://doi.org/10.1038/s41467-024-46934-0
H. Wang, J. Zhang, C. Shen, C. Yang, K. Küster, J. Deuschle, U. Starke, H. Zhang, M. Isobe, D. Huang, P. A. van Aken, and H. Takagi
Direct observation of the interplay between stacking polytypes and self-intercalation in epitaxial Nb1+xSe2 films,
BIO Web Conf. 129, 22022 (2024).
https://doi.org/10.1051/bioconf/202412922022
J. Deuschle, T. Heil, H. Wang, and P. A. van Aken
FIB-induced nanorod formation in 2D layered crystals,
BIO Web Conf. 129, 22032 (2024).
https://doi.org/10.1051/bioconf/202412922032
Y.-M. Wu, P. Puphal, M. Isobe, B. Keimer, M. Hepting, Y. E. Suyolcu, and P. A. van Aken
Unraveling nano-scale effects of topotactic reduction in LaNiO2 crystals,
APL Mater. 12, 091119 (2024).
https://doi.org/10.1063/5.0227732
S. Hayashida, V. Sundaramurthy, P. Puphal, M. Garcia-Fernandez, K.-J. Zhou, B. Fenk, M. Isobe, M. Minola, Y.-M. Wu, Y. E. Suyolcu, P. A. van Aken, B. Keimer, and M. Hepting
Investigation of spin excitations and charge order in bulk crystals of the infinite-layer nickelate LaNiO2,
Phys. Rev. B 109, 235106 (2024).
https://doi.org/10.1103/PhysRevB.109.235106
H. Wang, V. Harbola, Y.-J. Wu, P. A. van Aken, and J. Mannhart.
Interface Design beyond Epitaxy: Oxide Heterostructures Comprising Symmetry-Forbidden Interfaces,
Adv. Mater. 2405065 (2024).
https://doi.org/10.1002/adma.202405065
T. J. Whittles, S. C. Parks, H. Wang, P. Jiang, Z. Zhong, P. A. van Aken, and J. Mannhart.
Tailoring Work Functions of Heterostructures by Varying the Depth of a Buried Monolayer,
Adv. Mater. Interfaces 2400109 (2024).
https://doi.org/10.1002/admi.202400109
Y.-M. Wu, P. Puphal, H. Lee, J. Nuss, M. Isobe, B. Keimer, M. Hepting, Y. E. Suyolcu, and P.A. van Aken
Topotactically induced oxygen vacancy order in nickelate single crystals,
Phys. Rev. Materials 7, 053609 (2023).
https://doi.org/10.1103/PhysRevMaterials.7.053609
V. Srot, R. Straubinger, F. Predel, and P. A. van Aken
Preparation of High-Quality Samples for MEMS-Based In-Situ (S)TEM Experiments,
Microscopy and Microanalysis 29, 596–605 (2023).
https://doi.org/10.1093/micmic/ozad004
H. Wang, V. Srot, B. Fenk, G. Laskin, J. Mannhart, and P. A. van Aken
An optimized TEM specimen preparation method of quantum nanostructures,
Micron 140 102979 (2021).
https://doi.org/10.1016/j.micron.2020.102979