Title: Short- and long-range contributions to equilibrium and transport properties of solid electrolytes
Author(s):

	G. Bokun (Belarusian State Technological University, 13a Sverdlov St., 220006 Minsk, Belarus) ,
	I. Kravtsiv (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine) ,
	M. Holovko (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine) ,
	V. Vikhrenko (Belarusian State Technological University, 13a Sverdlov St., 220006 Minsk, Belarus) ,
	D. di Caprio (Institute of Research of Chimie Paris, CNRS-Chimie ParisTech, 11 rue Piere et Marie Curie, 75005 Paris, France)

Condensed ionic systems are described in the framework of a combined approach that takes into account both long-range and short-range interactions. Short-range interaction is expressed in terms of mean potentials and long-range interaction is considered in terms of screening potentials. A system of integral equations for these potentials is constructed based on the condition of the best agreement of the system of study with the reference system. In contrast to the description of media with short-range interactions, in this text the reference distribution includes not only the field of mean potentials but also Coulomb interaction between particles. A one-component system made of ions in a neutralizing background of fixed counterions is considered. The model can be used to describe solid ionic conductors. In order to study the movement of cations on the sites of their sub-lattice, the lattice approximation of the theory is employed based on the calculation of the pair distribution function. Using the collective variables approach, a technique improving the starting expression for this function is proposed. Notably, the neglected terms in the expansion of this function are approximated by single-particle terms ensuring that the normalization condition is satisfied. As a result, the applicability of the theory is extended to a wide region of thermodynamic parameters. The chemical potential and the diffusion coefficient are calculated showing the possibility of phase transitions characteristic of the system.

Key words: ceramic conductors, mean potentials, lattice approximation, collective variables method, pair distribution function, chemical potential
PACS: 5.20.-y, 61.72jd, 64.30.-t, 65.40.-b, 66.10-x

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