Evaluation of electrical conductivity of Fe-doped forsterite ceramics synthetized by sol–gel method

Abstract

This work aims to investigate the effect of sintering temperature and iron doping on the electrical conductivity of forsterite in the temperature range of 300–400 °C. For this purpose, olivine compositions (Mg2-xFexSiO4; x = 0, 0.05 and 0.1) were synthetized by sol-gel process and then characterized by different techniques. The obtained results indicate the successful formation of dense single phase olivine ceramics. It was also found that Fe inserted in forsterite lattice has both Fe (II) and Fe (III) oxidation states. Regarding the electrical conductivity, it turned out to be more sensitive to both investigation parameters, in contrast with the activation energy characterizing the diffusion of carriers charge responsible of electrical conductivity. The prepared samples were characterized by: XRD, SEM techniques and Raman, Mössbauer and impedance spectroscopies.