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Even-Parity Lattice Resonances And Anharmonicity In Ki: Ag+, Roger D. Kirby
Even-Parity Lattice Resonances And Anharmonicity In Ki: Ag+, Roger D. Kirby
Roger Kirby Publications
We report here the observation of four impurity-induced lattice resonances in KI:Ag+. In addition to the well-known T1u symmetry resonant mode at 17.3 cm-1, we have observed two even-parity resonant modes of A1g and Eg symmetries at 25 and 16.35 cm-1, respectively, and a T1u symmetry gap mode at 86.2 cm-1. The two even-parity modes were detected using far-infrared spectroscopic techniques with the sample in an external electric field. The field induces a strong mixing of the modes of opposite parity and results in large field-induced shifts. The Eg symmetry resonance has also been seen in the Raman spectrum of …
Low-Lying Even-Parity Resonances In Ki:Ag+, Roger D. Kirby
Low-Lying Even-Parity Resonances In Ki:Ag+, Roger D. Kirby
Roger Kirby Publications
Lattice resonances of Eg symmetry (16.35 cm-1) and A1g symmetry (25 cm-1) have been found in KI:Ag+ using far-infrared spectroscopic techniques. The two even-parity modes are found to be anharmonically coupled to the T1u- symmetry resonant mode at 17.3 cm-1, giving rise to the combination bands observed at 30 and 44.4 cm-1.
Far-Infrared Properties Of Lattice Resonant Modes. V. Second-Order Stark Effect, B.P. Clayman, Roger D. Kirby, A. J. Sievers
Far-Infrared Properties Of Lattice Resonant Modes. V. Second-Order Stark Effect, B.P. Clayman, Roger D. Kirby, A. J. Sievers
Roger Kirby Publications
Small electric-field-induced frequency shifts have been observed for resonant modes associated with three defect systems. For NaI: Clˉ, the shifts have been used to measure the quartic anharmonic terms of the interionic potential of the impurity ion. For KBr: Li+, the quartic anharmonic terms are found to be very small, and an harmonic potential which includes a central barrier with the barrier height less than the zero-point energy of the oscillator is required to explain the experimental results. For NaCl: Cu+, only an "on-center" resonant-mode configuration is consistent with the experimental results.