The Electrical Conductivity of CaO-SiO₂-Fe₂O₃ and Na₂O-SiO₂-Fe₂O₃ Melts

Abstract

The electrical conductivities of CaO-SiO₂-Fe₂O₃ and Na₂O-SiO₂-Fe₂O₃ melts were measured in order to find out the behavior of Fe₂O₃ in these systems. Since Fe³⁺ ion is the amphoterci cation, it may be assumed that Fe³⁺ ion in octahedral sites will contribute to the electrical conductivities of these melts, but not Fe³⁺ ion in tetrahedral sites.
In the Na₂O-SiO₂ system, the oxygen coordination number of Fe³⁺ ion is changed at Na₂O/Fe₂O₃\fallingdotseq1. When the ratio of Na₂O/Fe₂O₃ in the melt is less than unity, Fe³⁺ ion tends to contribute to the electrical conductivity as a network modifier. On the other hand, Fe³⁺ ion will give no contributions to the electrical conductivity at the composition of Na₂O/Fe₂O₃>1. The ratio of Fe^3+(oct.)/Fe^3+(tetr.) also varied with the basicity of melts.