Anomalous thermoelastic behaviour of orientationally disordered (NH4I)(x)(KI)(1-x) mixed crystals

作者：Tiwari Alpana^*; Gaur N K; Singh R K

来源：Journal of Physics and Chemistry of Solids, 2010, 71(5): 717-721.

DOI：10.1016/j.jpcs.2010.01.004

• Elastic properties
• Anharmonicity
• Thermodynamic properties

We have incorporated the translational rotational (TR) coupling effects in the framework of three body force shell model (TSM) to develop an extended TSM (ETSM). This ETSM has been applied to reveal the second order elastic constants (C-11, C-12 and C-44) in the dilute regimes 0 <= x <= 0.50. Our theoretical results have reproduced well the observed variations of C-11 (x=0.14, 0.43) and C-12 (x=0.14, 0.43) with temperature. The anomalous elastic behaviour observed in C-44 below 150 K for x=0.43 has been predicted well by ETSM results in the orientationally disordered (NH4I)(x)(KI)(1-x) mixed crystals. Our results for C-12 are in good agreement with the experimental data available for x=0.14 and 0.43. Besides, the third and fourth order elastic constants and the results on cohesive and thermophysical properties are also discussed.

• 出版日期2010-5