Regular Article

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite^★

¹ Laboratory of Materials Science, Faculty of Sciences Semlalia, B.P. 2390 Marrakech, Morocco
² Laboratory of Innovative Materials, Energy and Sustainable Development (IMED-Lab), Faculty of Sciences and Technology, Marrakech, Morocco

^* e-mail: saloua.el.asrii@gmail.com

Received: 1 June 2020
Received in final form: 20 August 2020
Accepted: 24 August 2020
Published online: 2 October 2020

Abstract

Forsterite single phase powder Mg₂SiO₄ was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg₂SiO₄. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.