Lorenz field correction

The Lorentz-Lorenz case in which the material is so microscopically inhomogeneous that the spatial distribution of OL is disjoint. The local-field correction is then L P,... 

Here Id sa /yl, 8 determines the correlation energy, X is extrapolation length of the film in paraelectric phase, E is a mean field in a bulk relaxor, d is the effective dipole moment corrected by Lorenz field, e is dielectric permittivity of a host film. 

The crudest approximation to the density matrix for the system is obtained by assuming that there are no statistical correlations between the elementary excitations (perfect fluid), so that can be written as a simple product of molecular density matrices A. A better approximation is obtained if one does a quantum field theory calculation of the local field effects in the system which in a certain approximation gives the Lorentz-Lorenz correction L(TT) in terms of the refractive index n53). One then writes,... 

The other two correction factors account for the effects of induced dipoles in the medium through electronic polarization, and are known as the Lorentz-Lorenz correction factors. The correction for the optical field at frequency 2fti is given by ... 

First, we consider a mixture obeying the Lorenz-Berthelot rules, such that f = 1 (cf. Eq. (49)). In Fig. 27 we show a p-T projection of the phase diagram as obtained from simulation and theory. The theory correctly predicts the vapor pressure of the pure components. However, the predicted critical temperatures are higher, as expected from a mean field theory. For this reason, the critical line of the mixture is described only in a qualitative manner. Particularly, the predicted critical pressures... 

---