High-Temperature Conductivity Measurements of Magnesium-Ion-Conducting Solid Oxide Using Mg Metal Electrodes

Abstract

The conductivity of polycrystalline pellets of Mg²⁺-ion-conducting solid oxide Mg_0.5−x(Zr_1−xNb_x)₂(PO₄)₃ (x = 0.15) with monoclinic β-Fe₂(SO₄)₃-type structure was measured with non-blocking Mg metal electrodes at 350 °C in vacuum using a high-temperature cell, which avoided the exposure of Mg electrodes to air before and during the measurements. At 350 °C dc and ac conductivities measured with Mg electrodes were consistent with ac conductivity measured with Pt electrodes. These observations evidenced that this compound is a pure Mg²⁺-ion conductor and stable in contact with Mg.