Anti-Stokes line is much less intense than the Stokes line. This occurs because only molecules that are vibrationally excited prior to irradiation can give rise to the anti-Stokes line. Hence, in Raman spectroscopy, only the more intense Stokes line is normally measured.
Water does have Raman scattering, but it is relatively weaker compared to other materials due to its symmetric molecular structure and low Raman cross-section. This makes it more challenging to detect and study using Raman spectroscopy.
Yes, they are. anti-stockes lines are less intense than stockes at room temperature because the no. of molecules in the lowest excited vibrational level is less than that in the next higher excited vib. level... and since the intensity of the lines depends on the population of molecules.... it have weaker lines.... but at thermal equilibriume.... the no. of molecules in the next higher excited vib. level is higher than that in the lowest one....so the intensity of the anti-stockes is higher than the stockes........!!!
The formula is: Wavelength of Stokes line = Wavelength of laser / (1 - wavenumber of Raman shift) Wavelength of anti-Stokes line = Wavelength of laser / (1 + wavenumber of Raman shift) Here, the wavenumber of the Raman shift is represented in reciprocal centimeters.
Wenxin Ke has written: 'Superconducting and kinetics of freezing of benzene clusters as studied by coherent Anti-Stokes Raman Spectroscopy' -- subject(s): Benzene, Supercooling, Spectra
It depends what you are looking for. There are online databases of Raman spectra for minerals, for example, e.g. https://www.fis.unipr.it/phevix/ramandb.php For characteristic functional groups/molecules and their peaks, it is better to consult a textbook of Raman Spectra, within which you can find tables of peak assignments - take a visit to the library!
In physics, Stokes lines and anti-Stokes lines are lines on a Raman spectrum that correspond to low and high energy shifts, respectively, due to inelastic scattering of light. Stokes lines occur at lower frequencies than the incident light, while anti-Stokes lines occur at higher frequencies than the incident light. These shifts provide information about the vibrational modes in a molecule.
Yes, Raman spectroscopy can be performed on metals and alloys to provide information about their molecular vibrations, crystalline structure, and chemical composition. However, since metals and alloys exhibit strong fluorescence and may not produce strong Raman signals, specialized techniques and equipment may be required to overcome these challenges.
Polarized Raman spectra refer to Raman scattering measurements where the incident and scattered light are polarized along specific directions. By using different polarization configurations, researchers can gather additional information about the orientation and symmetry of molecular vibrations in the sample. This technique is useful for studying anisotropic materials and understanding molecular structure and orientation.
Yes, there are different types of Raman spectroscopy, including spontaneous Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), and resonance Raman spectroscopy. Each type utilizes different methods to enhance the Raman scattering signal and provide insights into different sample properties.
Raman is used a lot as it is not sensitive to atmospheric water and CO2 usually won't stand out on the spectra. Its also useful in most settings as there is no sample prep needed, which is quite a difference to somthing like IR spectra which need nujol mulls or KBr plates. In comparison to IR the bands of the spectra are usually smaller and sampling is non-destructive. In an industrial setting raman can be used with fiber optic cables to remotely monitor reactions and product formation.
Kirk W. Brown has written: 'Coherent raman spectroscopy of non-polar molecules and molecular clusters' -- subject(s): Carbon dioxide, Raman spectroscopy, Spectra
Anne Hamilton McKague has written: 'Vibrational Raman spectra of hydrogen and deuterium in the condensed phases' -- subject(s): Raman effect, Physics Theses, Hydrogen, Deuterium