Like FTIR, Raman micro-spectroscopy is based on molecular vibrations. It permits qualitative or semi-quantitative determination of the molecular composition of a wide range of materials.
To perform the measurements, a laser beam is directed on the sample which interacts with phonons inside the microstructure, thus creating an emission at another wavelenght. This technique has recently made an important resurgence because of the development of extremely sensitive detectors, able to process the extremely weak signal generated by the Raman effect.
Type of materials: Solids and liquids, organics and some inorganic solids
Type of information: molecular
Precision: Qualitative or semi-quantitative
Detection limit: about 5%
Depth of analysis: up to 2.5 microns
Smallest measurable area: 1 micron
-Identification of the molecular composition (on the surface and in depth)
-Analysis of coatings and thin films
-Extremely versatile technique
-Analysis of very small areas
-Some samples do not respond well to the analysis (hard to predict)
-The interpretation of the results can be difficult for complex samples
Resolution : 2 – 5 cm-1 , ≥1% masse
Depth resolution : 2 µm
Lateral resolution : 1 µm
Other characteristics : wavelengths : 488 nm, 514 nm, 633 nm, 782 nm, variable wavelength between 750 and 900 nm, point by point mapping and depth profiling, confocal mode, Raman imaging, photoluminescence measurements, polarization measurements, SERS and line focus, temperature : -196 °C to 600 °C.
Manufacturer : Renishaw
Model : RM3000, InVia Reflex
Manufacturer : ISA
Model : U1000
Manufacturer : PI-Acton
Model : TriVista