Ferroelectric phase transition in simple dipolar systems

A simple version of the linear hypervertex approximation (LHA) is used to estimate the location of ferroelectric transitions in dipolar systems. The well known result of the mean-spherical approximation is used to develop an explicit expression for the core parameter that appears in our mean-field theory of dipolar systems (J. S. Høye and G. Stell, 1976, J. chem. Phys., 64, 1952). The full self-consistent version of the LHA, not as yet assessed numerically, promises to be of higher quantitative accuracy. For the comparatively low values of the dielectric constant that characterize real molecular dipolar fluids, the LHA may well be the best analytic theory currently available for that quantity.