Oxide ion conduction in the perovskite-type LaYO3 doped with ZrO2

Abstract

In order to find a new type of oxide ion conductor, the electrical conduction was measured in the substituted perovskite-type oxides. In the present case, LaYO3 was used as a based material with an orthorhombic and comparatively large unit cell, and a novel substitution method was introduced to intend to increase the concentration of oxide ions, e.g., LaY 1-xZrxO3+x/2. As a result, the LaYO 3-based perovskite-type solid solution was found to be formed, where the enhanced oxide ion conduction was observed as compared with that of the based material. A typical sample was LaY0.95Zr0.05O 3.025, the ionic conduction of which was 1.2 × 10-2 S cm-1 at 1000 °C. Another substitution method of La 1-xZrxYO3+x/2 resulted in the analogous result. Considering these results and the further structural and density measurements, the charge carriers in these phases were expected to be due to interstitial oxide ions.