TEMPERATURE-DEPENDENCE OF ELASTIC-CONSTANTS AND THERMAL-EXPANSION COEFFICIENT FOR NACL-CRYSTALS

The second-order elastic constants C-11, C-12, and C-44, isothermal bu lk modulus B-T, and Volume thermal expansion coefficient alpha are cal culated for NaCl crystals in the temperature range (294 to 766 IC) usi ng Tallon's model based on the concept of modified Anderson-Gruneisen parameters. The results obtained in the present study are compared wit h the experimental Values reported in the literature. There is good ag reement between calculated and experimental Values for V/V-0, C-11, C- 44, B-T, and alpha. It is found that C-11, C-44, and B-T decrease wher eas C-12 and alpha increase with increase in temperature.