4 research outputs found
Ferro-electric phase transition in a polar liquid and the nature of \lambda-transition in supercooled water
We develop a series of approximations to calculate free energy of a polar
liquid. We show that long range nature of dipole interactions between the
molecules leads to para-electric state instability at low temperatures and to a
second-order phase transition. We establish the transition temperature, T_{c},
both within mean field and ring diagrams approximation and show that the
ferro-electric transition may play an important role explaining a number of
peculiar properties of supercooled water, such as weak singularity of
dielectric constant as well as to a large extent anomalous density behavior.
Finally we discuss the role of fluctuations, shorter range forces and establish
connections with phenomenological models of polar liquids.Comment: 5 pages, 1 eps figure, density anomaly at T=4C analysis adde
Experimental evidence of the ferroelectric phase transition near the point in liquid water
We studied dielectric properties of nano-sized liquid water samples confined
in polymerized silicates MCM-41 characterized by the porous sizes \sim 3-10nm.
We report the direct measurements of the dielectric constant by the dielectric
spectroscopy method at frequencies 25Hz-1MHz and demonstrate clear signatures
of the second-order phase transition of ferroelectric nature at temperatures
next to the \lambda- point in the bulk supercooled water. The presented results
support the previously developed polar liquid phenomenology and hence establish
its applicability to model actual phenomena in liquid water.Comment: 4 pages, single figur