The oxygen-exchange behavior has been studied in half-doped manganese and cobalt perovskite oxides. We have found that the oxygen diffusivity in Gd_{0.5}Ba_{0.5}MnO_{3-\delta} can be enhanced by orders of magnitude by inducing crystallographic ordering among lanthanide and alkali-earth ions in the A-site sublattice. Transformation of a simple cubic perovskite, with randomly occupied A-sites, into a layered crystal GdBaMn_2O_{5+x} (or isostructural GdBaCo_2O_{5+x} for cobalt oxide) with alternating lanthanide and alkali-earth planes reduces the oxygen bonding strength and provides disorder-free channels for ion motion, pointing to an efficient way to design new ionic conductors.
@article{arxiv.cond-mat/0501127,
title = {Achieving fast oxygen diffusion in perovskites by cation ordering},
author = {A. A. Taskin and A. N. Lavrov and Yoichi Ando},
journal= {arXiv preprint arXiv:cond-mat/0501127},
year = {2007}
}
Comments
4 pages, 4 figures, accepted for publication in Appl.Phys.Lett