Analysis of elastic constants and thermal energy of ionic materials

Expressions for the temperature dependence of elastic constants have been formulated by taking into account volume dependence of the Anderson-Gruneisen parameters. These expressions have been applied to ionic materials such as NaCl, KCl, MgO, and CaO to determine elastic constants at different temperatures. It is found that the linear relationship between isothermal bulk modulus and thermal energy ([E.sub.th]) is also applicable to other elastic constants. This linear relationship is valid, starting from room temperature. PACS Nos: 62.20, 65.70, 65.40.-b Nous avons obtenu des expressions pour la dependance en temperature des constantes elastiques, en tenant compte de la dependance en volume des parametres de Anderson-Gruneisen. Nous avons applique ces expressions aux materiaux ioniques NaCl, KCl, MgO et CaO, afin de determiner leurs constantes elastiques a differentes temperatures. Nous trouvons que la relation lineaire entre le module d'elasticite isostatique isotherme et l'energie thermique ([E.sub.th]) peut aussi s'appliquer a d'autres constantes elastiques. Cette relation lineaire est valide a partir de la temperature ambiante. [Traduit par la Redaction]
1. Introduction Knowledge of elastic constants is necessary for an understanding of various fundamental properties such as interatomic potentials, specific heat, thermal expansion, Debye temperature, melting point, and the Gruneisen [...]