A symmetric critical behaviou r of binary mixtu res

The mo st importa nt feature of critical be havior is universality class of ۳D -Ising-like systems which indicates sufficiently close to the critica l point, because of the large critical fluctuations, syste ms of differ ent physic al natures m ay exhibit similar critical behavior. Near the critical region of a binar y solution, the different of the g eneral density variable of two coexisting phasesΔPCXC can be described by universal power-law of the reduced temperature ΔTnear the critical point as:(...)whereο ΔT=(...)isthe critical temperatu re,P is the general density variab le, such as refractive index, mole, frac tion and volume fraction, the sub scripts ۱ and ۲ represent upper and low er phases r espectively ,B۰ is the c ritical amplitude and B is the critical expon ent. For ۳D-Ising universality class its value is ۰.۳۲۶.This asymmetric criticality h as been paid muchattention in recent decade accompanied by the raise of the concept of the complete scaling propose d by Fisher and co-w orkers, whi ch shows th at the scaling fields sh ould be considered as a linear combin ation of all physical fields [۱]. C omplete sc aling turns out to cause a so-called Yang-Yang anomaly for the temp erature dep endence o f the heat capacity in the two-phase region. Furthermore, the heat capacity plays an important role in descri bing the asymmetric criticality within the fr ame of th e complete scaling theory. Recently Anisimovand et al. have extended the complete scaling to binary mixt ures and tested the complete scaling by analysing experimen tal coexisting curve data for a ser ies of bina ry liquid mixture s [۲].

کلیدواژه ها:

Coexistence curv e ، Binary m ixtures ، Mole fraction ، Refractiv e index