Local atomic structure in cubic stabilized zirconia - art. no. 104101

X-ray-absorption fine structure measurements have been used to elucidate th e local atomic structure of quaternary Zr, Y, Er, Ce/U cubic stabilized zir conia. These compounds display more complicated local environments than tho se reported for simpler binary systems. While the shortest cation-O distanc es are similar to those found in the binary cubic stabilized compounds, res ponding to the different sizes of the cations, we have identified large dis tortions in the first-shell oxygen distribution involving long, 2.8-3.2 Ang strom cation-O distances that are similar to those found in the amorphous p hase of zirconium. The cation-cation distributions are also found to be qui te complicated (non-Gaussian) and element specific. The U-near neighbor dis tances are expanded relative to the Ce ions for which it substitutes, consi stent with the larger size of the actinide, and the U-cation distribution i s also more complicated. In terms of the effects of this substitution on th e other cation sites, the local environment around Y is altered while the Z r and Er local environments remain unchanged. These results point out the i mportance of collective and correlated interactions between the different p airs of cations and the host lattice that are mediated by the local strain fields generated by the different cations. The presence of pair-specific co uplings has not been commonly included in previous analyses and may have im plications for the stabilization mechanisms of cubic zirconia.