Raman-in-SEM, a multimodal and multiscale analytical tool: performance for materials and expertise

Area of Science:

• Materials Science
• Analytical Chemistry
• Geosciences

Background:

• Conventional analytical techniques require sample transfer between instruments, limiting efficiency.
• Integrating Raman spectroscopy within a scanning electron microscope (SEM) offers simultaneous morphological, elemental, and chemical analysis.
• The SEMSCA commercial Raman interface provides a novel solution for in-situ multimodal characterization.

Purpose of the Study:

• To document the metrological performance of the SEMSCA Raman interface in a low vacuum SEM.
• To evaluate multiscale and multimodal analyses, including Raman/EDS, Raman/cathodoluminescence, and Raman/STEM.
• To investigate and mitigate SEM-related artifacts affecting Raman spectra, particularly in geological samples.

Main Methods:

• Operation of the SEMSCA Raman interface within a low vacuum SEM.
• Comparison with a conventional micro-Raman spectrometer.
• Implementation of multimodal analyses (Raman/EDS, Raman/CL, Raman/STEM) and nanomaterial characterization.
• Methodology for overcoming electron beam-induced contamination and cathodoluminescence interference, including SEM beam shutter use.

Main Results:

• The SEMSCA interface demonstrates effective multiscale and multimodal analytical capabilities.
• Artifacts such as electron beam-induced contamination and cathodoluminescence contributions were identified and addressed.
• Optimized SEM and Raman settings, including a SEM beam shutter, successfully mitigated adverse effects.
• The interface allows for simultaneous acquisition of Raman and cathodoluminescence spectra.

Conclusions:

• The SEMSCA Raman interface offers efficient and powerful multimodal characterization directly within a SEM.
• This integrated approach simplifies analysis and enhances insights, particularly for geosciences applications.
• The ability to overcome SEM-related artifacts makes this a valuable tool for advanced materials analysis.