Raman Spectroscopy (Raman)

Raman Spectroscopy (Raman) enables you to determine the chemical structure of a sample and identify the compounds present by measuring molecular vibrations, similar to Fourier Transform Infrared Spectroscopy (FTIR). However, the method used with Raman yields better spatial resolution and enables the analysis of smaller samples.

Raman is a good technique for the qualitative analysis of organic and/or inorganic mixed materials and can also be employed for semi-quantitative and quantitative analysis. It is often used to:

• Identify organic molecules, polymers, biomolecules, and inorganic compounds both in the bulk and in individual particles
• Raman imaging and depth profiling is used to map the distribution of components in mixtures, such as drugs in excipients, tablets, and drug-eluting stent coatings
• Determine the presence of different carbon types (diamond, graphitic, amorphous carbon, diamond-like carbon, nanotubes, etc.) and their relative proportions, something for which it is particularly well suited
• Determine inorganic oxides and their valence state
• Measure the stress and crystalline structure in semiconductor and other materials

Evans Analytical Group® (EAG) offers our customers Raman services to analyze small contamination areas, identify materials in small areas, and measure stress. The resulting data helps our clients resolve problems quickly, reduce cycle times, and improve production processes. We believe that no competing lab can match the skill set and experience of our staff. Plus, you can count on fast turnaround times, accurate data, and person-to-person service, ensuring you understand the information that you receive.

View Application Notes

Ideal Uses for Raman Analysis		Relevant Industries for Raman Analysis
Identifying the molecular structure of organic and inorganic compounds for contamination analysis, material classification, and stress measurements Characterization of carbon layers (graphitic v. diamond) Non-covalent bonding (complexes, metal bonding) Orientation (random v. organized structure)		Aerospace Automotive Biomedical/biotechnology Compound Semiconductor Data Storage Defense Displays Electronics Industrial Products Lighting Pharmaceutical Photonics Polymer Semiconductor Solar Photovoltaics Telecommunications
Strengths of Raman Analysis		Limitations of Raman Analysis
Capable of identifying organic functional groups and often specific organic compounds Spectral libraries for compound identification Ambient conditions (not vacuum; good for semi-volatile compounds) Typically non-destructive Minimum analysis area: ~1 µm		Limited surface sensitivity (typical sampling volumes are ~0.8 µm) Minimum analysis area: ~1 µm Limited inorganic information Typically not quantitative (needs standards) Fluorescence (much more intense than the Raman signal) can limit Raman usefulness

Application Notes