A unified equation for modeling the dependency of conductivity with temperature in ionic systems

• Published in: Physica A Vol. 525; pp. 635 - 641
• Main Authors: Palchucan, C.A., Lara, D. Peña, Correa, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2019
• Subjects: Arrhenius equation; Modeling of ionic conduction; Transport dynamics in ionic conductors; Unified equation; VTF model; Arrhenius equation; Transport dynamics in ionic conductors; Unified equation; VTF model; Modeling of ionic conduction
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/j.physa.2019.03.052

One of the most significant features in understanding transport dynamics in ionic conductors is the behavior of the activation energy with temperature. Several mathematical equations to fit conductivity curves, as a function of temperature for all kinds of solid compounds and liquid electrolytes have been used. These curves are generally linear functions or curves that have either positive or negative concavities or a combination of both. In order to fit these curves, three types of commonly accepted functions are available in the literature: Arrhenius function for the linear case, the VTF function for negative concavities, and polynomial and exponential functions for positive concavities. The use of one or the other leads to the formulation of a conduction model that lies behind each equation or equation set, and the interpretation of fitting constants depends on the physical system. In this work a single empirical equation fitting the three types of behavior mentioned above for different ionic systems is proposed. •A unified phenomenological model for ionic conduction is proposed.•Empirical equation to fit three types of behavior for ionic conduction is presented.•Existence of a great number of contributions to polarization energies is verified.