JOURNAL OF CHEMICAL PHYSICS, vol.118, no.13, pp.5947-5954, 2003 (SCI-Expanded)
Critical behaviors of the sound attenuation in a spin-1 Ising system with bilinear (J) and biquadratic (K) interactions are investigated within the framework of cluster variation method and Onsager theory of irreversible thermodynamics. The sound wave is assumed to couple mainly to the order parameter fluctuations which decay via order parameter relaxation processes. Two relaxation times are obtained and an expression is found for the sound attenuation coefficient (alpha) in terms of these relaxation times. The temperature behavior of the sound attenuation near the phase transition temperatures (T-c) is analyzed according to various values of Onsager coefficients (gamma(ij)) and sound frequency (omega). For T