Mixed cation and mixed anion effects in sodium sulphate and lithium-tungsten-phosphorus oxides glasses

¹ Laboratoire d’Ingénierie des Matériaux Organométalliques, Moléculaires, Environnement (IMOME), Université Sidi Mohamed Ben Abdellah, B.P. 509, Boutalamine, 52000, Morocco ;
² Laboratory of Engineering Sciences and Professions, National School of Arts and Crafts, Moulay Ismail University, Meknes, Morocco ;
³ Chemistry-Physics, Electrochemistry, and Environment Team, Faculty of Science and Technology, Moulay Ismail University, Er-Rachidia, Morocco ;
⁴ Laboratory of Materials Physiochemistry and Environment (LPCME), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, Morocco.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The density, activation energies, and electrical conductivity of ionic conductive glasses containing xNaSO₄-(0.5-x)Li₂O-0.125WO₃-0.375P₂O₅ based on molar fractions (x = 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 % mol). Densities vary linearly with the content of N₂SO₄. The relationship between temperature and total conductivity was analysed using the Arrhenius equation. A set of parallel lines was observed, which means that the electronic and ionic conductivities of these glasses follow Arrhenius' law on the one hand, and on the other hand, that their activation energies are very close. The evolution of the relaxation time τ_σ, and electrical conductivity σ_dc, pre-exponential term σ₀, activation energies E_aσ and E_af and frequency f₀ depending on content in Na₂SO₄ does not vary linearly and passes through a pronounced minimum or maximum in the glasses studied therein. This phenomenon is due to the mixed cation exchange effect (MCE) and/or mixed anion exchange effect MAE. These effects in these glasses can be explained using the rigidity theory developed by Phillips and Gupta.