Condensed Matter Physics, 1995, No. 5, p. 57-73, English
DOI:10.5488/CMP.5.57
Title: Gaussian and nongaussian basic measure densities in the
theory of cluster ferroelectrics
Authors: N.A. Korynevskii
The problem of application of Gaussian and non-Gaussian basic measure densities
of
collective variables for integration a cluster ferroelectric partition
function functional is discussed. Starting from the conver- gence of
functional integrals in the phase transition point vicinity the first
Brillouin zone is divided into layers. Every layer consists of two parts.
In the first one the Gaussian measure density is sufficient and in the
second one the non-Gaussian measure density must be used. The partition
function obtained as a result of layer by layer integration is finite in
the temperature region which contains the neighbourhood of phase
transition point. The critical behaviour of a thermodynamic functions is
studied.