Dual-beam FIB/SEM with plasma ion column (plasma-FIB/SEM)

• Subject Area: Materials Science
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550137998

Interfaces, surfaces, and phases play a crucial role in the performance of energy, functional, and structural materials. Transmission electron microscopy (TEM) and atom probe tomography (APT) are essential characterization techniques for providing details of the structure, composition, and elemental distribution at the interfaces, surfaces, or phases of the materials. The quality of the TEM and APT specimens is essential for determining the data quality and interpretation. However, the specimens prepared by Ga+-focused ion beam scanning electron microscopy (FIB/SEM) often suffer from Ga+ implantation and amorphous damage on the surface and in the bulk of the materials. These inevitable artifacts generate erroneous data and restrain us from imaging or analyzing the ‘native’ state of the high-performance materials, hindering the correlation of structure-performance-processing relationships. In this context, a multi-ion plasma FIB/SEM, at least with Xe and Ar plasma ion species, is urgently needed to prepare Ga+-free APT and TEM specimens with minimal damage on the surface and bulk part of the materials. The flexibility of switching plasma ion species will enable us to adapt plasma FIB/SEM to our diverse materials applications and research purposes. Specifically, the Xe plasma ions generally have the highest sputter yield, allowing us to perform efficient high-volume milling or cross-section cutting at high beam currents. The Ar plasma ions are particularly effective for milling curtaining-free cross-sections of, e.g., battery electrodes; a smooth cross-section is indispensable for imaging and performing compositional analysis at battery interfaces. Additionally, Ar+ plasma milling creates the least sample damage at low kV, which can fabricate high-quality TEM lamellas for advanced analysis. To unlock the full potential of the multi-ion plasma FIB/SEM, we request the following key configurations: retractable backscattered detector, scanning TEM detector, nanomanipulator, energy-dispersive X-ray spectroscopy detector, electron backscatter diffraction detector, multiple chemistry gas injection system, and docking system to un/load our existing cryogenic ultra-high vacuum suitcase for transporting air- or humidity-sensitive materials. These configurations will empower multi-ion plasma FIB/SEM to perform high-throughput bulk milling, curtaining-free cross-sectioning, high quality and Ga+-free TEM and APT specimen preparation, and advanced microstructure analysis. The proposed multi-ion plasma FIB/SEM will meet the increasing requirements of the diverse materials research activities at Ruhr University Bochum, aiding in developing mechanically, chemically, and physically dominated high-performance materials.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Zweistrahlrasterelektronenmikroskop mit Plasma-Ionensäule (Plasma-FIB/REM)
• Instrumentation Group: 5120 Rasterelektronenmikroskope (REM)
• Applicant Institution: Ruhr-Universität Bochum
• Leader: Professorin Tong Li, Ph.D.