Lattice Dynamics and Second-Order Raman Spectrum of NaF
- 15 March 1969
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 179 (3), 837-845
- https://doi.org/10.1103/physrev.179.837
Abstract
The second-order Raman spectrum of NaF has been measured using an argon laser source. For a light beam incident along the [010] direction, polarized along the [001] direction, and viewed along the [100] direction, the scattered radiation is almost completely polarized. It is shown theoretically that it is possible to account for the polarization and the detailed shape of the observed spectrum within the experimental resolution using a Raman polarizability tensor whose second derivatives with respect to nuclear displacements depend only on the positions of first neighbors in the crystal, provided one uses the phonon frequencies derived from a deformation dipole model that includes second-neighbor interactions. By assuming that the polarizability is affected only by central displacements of the nearest neighbors, the number of independent polarizability derivatives is reduced from eight to three. This assumption also gives a vanishing depolarized intensity in agreement with the experimental results. The second-order difference spectra have also been evaluated, and are found to be much more sensitive to the relative magnitudes of the various polarizability derivatives.
Keywords
This publication has 9 references indexed in Scilit:
- Lattice Dynamics and Second-Order Raman Spectrum of CsFPhysical Review B, 1968
- Lattice Dynamics and Specific-Heat Data of CsCl, CsBr, and CsIThe Journal of Chemical Physics, 1968
- Room-Temperature Second-Order Raman Spectra of CsCl, CsBr, and CsIPhysical Review B, 1967
- Lattice Dynamics of Sodium FluoridePhysical Review B, 1967
- Precise Vibrational Frequency Distributions and the Second-Order Raman Spectrum and Specific Heat of NaClPhysical Review B, 1966
- Theory of the first-order Raman effect in crystalsProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1963
- Critical Points and Lattice Vibration SpectraPhysical Review B, 1956
- The Occurrence of Singularities in the Elastic Frequency Distribution of a CrystalPhysical Review B, 1953
- Raman Spectrum of RocksaltNature, 1949