Ramanspektroszkópiában

Ramanspektroszkópia, also known as Raman spectroscopy, is a spectroscopic technique used to study vibrations of molecules. It is a type of inelastic scattering of a monochromatic light, usually from a laser in the visible, near-infrared, or near-ultraviolet range. When light interacts with a sample, most of it is scattered elastically at the same wavelength (Rayleigh scattering). However, a small fraction of the light is scattered inelastically, meaning the scattered photons have different energies and thus different wavelengths compared to the incident photons. This energy difference is due to the vibrational modes of the molecules in the sample.

The inelastic scattering, known as Raman scattering, occurs when the incident photons transfer energy to or gain energy from the molecular vibrations. If a photon loses energy to a molecule, it is called Stokes scattering, resulting in a longer wavelength. If a photon gains energy from a molecule, it is called anti-Stokes scattering, resulting in a shorter wavelength. The energy gained or lost corresponds to the energy of specific molecular vibrational modes.

The Raman spectrum is a plot of the intensity of the scattered light versus the Raman shift, which is the difference in energy between the incident and scattered photons, typically expressed in wavenumbers (cm⁻¹). Each peak in the Raman spectrum corresponds to a specific vibrational mode of the molecule. This allows for the identification and characterization of chemical compounds, as different molecules have unique vibrational fingerprints.

Raman spectroscopy is a non-destructive technique and can be used to analyze samples in various states, including solid, liquid, and gas. It is widely applied in fields such as chemistry, physics, materials science, biology, and medicine for chemical analysis, structural elucidation, and process monitoring.