Thermoelastic behaviour of orientationally disordered NH4Br

Abstract

We have investigated the second and third order elastic constants of orientationally disordered NH4Br using an Extended Three Body Force Shell Model (ETSM) in the temperature range 240 K ≤ T ≤ 320 K. The second order elastic constants (C11, C12 and C44) obtained by us show an anomalous behaviour with the variation of temperature. The variation of the second and third order elastic constants with temperature are in good agreement with the measured data. Besides, the results on cohesive and thermal properties are also discussed. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.