The Wavelet-Analysis at MonteCarlo Modeling of Phase Transitions in a Ferroelastic Crystal of Lithium Ammonium Sulphate

摘要

Using methods of the wavelet—analysis at Monte—Carlo modeling a behavior of ther-modynamic parameters of Ising model for the ferroelectric—ferroelastic crystal oflithium ammonium sulphate LiNH_4SO_4 is studied. The discussed method is similar toMonte—Carlo Renormalization Group (MCRG), but it is more effective, thanks to apresence of algorithm of fast wavelet–transformation (WT). The short review of thewavelet transform and Monte—Carlo modeling by means of MCRG algorithm has beenmade. Temperature dependences of a specific heat capacity and dielectric permittivityfor a set of lattice models with the sizes N x N at N = 64, 128, and 256 were derived asa result of 1, 2, 3-level WT. Critical exponents are found by numerical differentiation ofa temperature dependence of thermodynamic parameters near a temperature of phasetransition.