WITec Alpha 300 Access with confocal microscope
(WITec Wissenschaftliche Instrumente und Technologie GmbH)
Raman spectroscopy is the study of solids with the aid of inelastic scattering from its molecules and is used, among other things, to investigate material properties such as chemical composition, crystallinity, crystal orientation or doping. The spectroscopy method is based on the Raman effect.
In order to use Raman spectroscopy, the polarizability must change when the molecules of the sample rotate or vibrate. In Raman spectroscopy, the material under investigation is irradiated with monochromatic laser light (532 nm, 30 mW). The irradiated light interacts with the molecules of the sample under investigation and excites or deactivates vibrations or rotations, for example. Therefore, in addition to the irradiated frequency (Rayleigh scattering), other frequencies can be observed in the spectrum of the light scattered by the sample. The frequency differences to the irradiated light correspond to the energies of rotation, oscillation, phonon or spin-flip processes characteristic for the material, allowing conclusions to be drawn about the material under investigation.
