U Band in Cesium Halides
| Autor: | G. A. Tanton, R. A. Shatas, S. S. Mitra, R. S. Singh |
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| Rok vydání: | 1972 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 56:5963-5969 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.1677142 |
| Popis: | The U band shape in CsCl, arising from the first singlet to singlet electronic transition of substitutional H− and D− impurities replacing the anions, has been measured in the temperature range of 8–300°K. At 8.4°K, the absorption peak and half width for the H− center were found to be 5.425± 0.005 and 0.24± 0.005 eV, respectively; while those for the D− center were 5.440± 0.005 and 0.21± 0.005 eV, respectively. Along with the previously obtained data for CsBr and CsI, the U band peak position was found to follow Mollwo‐Ivey relation having the exponent of the near‐neighbor distance of −1.54. The U band shape in CsCl has been analyzed by the method of moments. The temperature dependence of the half‐width can be explained by means of an effective phonon frequency. The single effective phonon frequencies of the U band in CsCl‐type crystals were compared with the weighted mean phonon frequencies of the host crystals obtained from a recent lattice‐dynamical calculation. Little correlation was noted. |
| Databáze: | OpenAIRE |
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