Oxide ion transport in (Nd2−xZrx)Zr2O7+δ electrolytes by an interstitial mechanism

Shlyakhtina, AV; Belov, DA; Knotko, AV; Avdeev, M; Kolbanev, IV; Vorobieva, GA; Karyagina, OK; Shcherbakova, LG

Oxide ion transport in (Nd2−xZrx)Zr2O7+δ electrolytes by an interstitial mechanism

Date

2014-08-05

Authors

Publisher

Elsevier

Abstract

We have studied the structure and transport properties of ten (Nd2−xZrx)Zr2O7+x/2 (x = 0–1.27) solid solutions, which lie in the ZrO2–Nd2Zr2O7 isomorphous miscibility range. Major attention has been focused on the pyrochlore-like (Nd2−xZrx)Zr2O7+x/2 solid solutions with x = 0–0.78, which are thought to be potential interstitial oxide ion conductors. The X-ray and neutron diffraction results demonstrate that the (Nd2−xZrx)Zr2O7+x/2 (x = 0–1.27) solid solutions undergo an order–disorder (pyrochlore–defect fluorite) structural phase transition. The (Nd2−xZrx)Zr2O7+x/2 (x = 0.2–0.78) have the bulk conductivity, ∼(1.2–4) × 10–3 S/cm at 750 °C, which is two orders of magnitude higher than that of the ordered pyrochlore Nd2Zr2O7. An attempt has been made to determine the interstitial oxygen content of (Nd2−xZrx)Zr2O7+x/2 (x = 0.2; 0.67) in a reducing atmosphere using thermogravimetry and mass spectrometry. It has been shown that no reduction occurs in the NdZrO system, where neodymium has only one oxidation state, 3+. © 2014, Elsevier B.V.

Keywords

Fuel cells, Oxides, Neutron diffraction, Solubility, Fluorite, Neodymium

Citation

Shlyakhtina, A. V., Belov, D. A., Knotko, A. V., Avdeev, M., Kolbanev, I. V., Vorobieva, G. A., Karyagina, O. K., & Shcherbakova, L. G. (2014). Oxide ion transport in (Nd2−xZrx)Zr2O7+δ electrolytes by an interstitial mechanism. Journal of Alloys and Compounds, 603, 274-281. doi:10.1016/j.jallcom.2014.03.068