Charge Raman spectroscopy

In pyrroelecttic devices, a charge is developed across the film in response to heating and such devices may serve as k-detectors (see Infrared TECHNOLOGY AND RAMAN SPECTROSCOPY). Pie2oelecttic appHcations are promising as sound detectors, because for these, a charge is developed across the film in response to pressure. A review is available (74). 

Transient Raman spectroscopy was also used to study charge transfer reactions across aqueous solution interfaces. One optical pulse above the band gap creates... 

Accordingly, the selection rules for Raman and IR spectroscopy are different. In Raman spectroscopy, there must be a change in the molecule s polarizability upon excitation, whereas a change in dipole moment is required for IR. A dipole moment is the magnitude of the electronic force vector between the negative and positive charges or partial charges on a molecule. A permanent dipole moment exists in all polar mol-... 

Raman and IR spectroscopies are complementary to each other because of their different selection rules. Raman scattering occurs when the electric field of light induces a dipole moment by changing the polarizability of the molecules. In Raman spectroscopy the intensity of a band is linearly related to the concentration of the species. IR spectroscopy, on the other hand, requires an intrinsic dipole moment to exist for charge with molecular vibration. The concentration of the absorbing species is proportional to the logarithm of the ratio of the incident and transmitted intensities in the latter technique. 

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