Thermoelastic Behaviour of Orientationally Disordered (NH4Br) x (KBr) 1-x

摘要

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 as a function of temperature for 0K?T?320K. The anomalous elastic behaviour in C 44 has been depicted well by ETSM results in the orientationally disordered (NH 4 Br) x (KBr) 1-x mixed crystals. In order to present a visual comparison of the TR-coupling effect on second order elastic constants, we have evaluated the SOECs with and without TR coupling term in ETSM.