Temperature Dependence of Fourth-Order Elastic Constants of Alkali Halide Crystals

✍ Scribed by R. K. Varshney; J. Shanker

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 553 KB
• Volume: 129
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221290106

✦ Synopsis

Abstract

A method for evaluating the temperature dependence of fourth‐order elastic constants (FOEC) of NaCl as well as CsCl‐structure alkali halides is developed on the basis of the phonon‐pressure theory. Eleven distinct values of FOEC for each alkali halide crystal are calculated at 0 K and at room temperature (300 K). The pressure derivatives of second and third‐order elastic constants are calculated at both the temperatures. The method is based on the phonon‐pressure theory incorporating Lundqvist's three‐body potential. The second‐order temperature derivatives of second‐order elastic constants are also evaluated. The results obtained are discussed and compared with other investigations. The importance and significance of temperature contributions to various order elastic constants are discussed.