Dielectric and anharmonic behaviour of alkali halide crystals

✍ Scribed by J. Shanker; R. Sundaraj

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 458 KB
• Volume: 114
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221140244

✦ Synopsis

Abstract

The dielectric and anharmonic behaviour of alkali halide crystals is studied by determining the volume derivatives of low frequency dielectric constant and polarizability. An interionic force model which takes into account the contributions arising from the short range overlap repulsion and the van der Waals interactions is used in calculations. The implicit and explicit temperature derivatives of low frequency and high frequency dielectric constants are obtained separately for all the alkali halide crystals with NaCl and CsCl structures. The anharmonic contribution to the dielectric constant is calculated using theoretical models due to Szigeti and Havinga. The recent analysis of pressure dependence of effective charge parameter and dielectric constant of ionic crystals performed by Varotsos is shown to be invalid.