Comments on the Theory of Anharmonic and Tunnel-Phonon Interactions in KCl:Li+

✍ Scribed by Giorgio Benedek

• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 688 KB
• Volume: 43
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2220430208

✦ Synopsis

Abstract

The local third‐order anharmonicity, the tunnel splitting of phonon levels, and the interaction between phonons and tunnel excitations, occurring for an off‐centre defect ion in crystals, are considered in connection with the resonant mode isotope shift. The phonon self‐energy related to the above interactions is evaluated to the lowest order of perturbation theory. The first two mechanisms are found to be responsible for the anomalous isotope shift recently discovered by Kirby and Sievers in KCl:Li^+^.