[Zurück]

J.-S. Lee, J. Fleig, J. Maier, D.-Y. Kim, T.-J. Chung:
"Local Conductivity of Nitrogen-Graded Zirconia";
Journal of the American Ceramic Society, 88 (2005), S. 3067 - 3074.

Conductivity profiles of nitrogen-graded zirconia from nitridation of 2 mol% yttria-doped tetragonal zirconia polycrystals (2Y-TZP) were determined using microcontact impedance spectroscopy. Local conductivity variations were interpreted in terms of nitrogen concentration and the morphological distribution of the tetragonal precipitates in the two-phase region of nitrogen partially stabilized zirconia (N-PSZ). Nitrogen incorporation in the stabilized zirconia was found to strongly decrease the local conductivity below 400°C, even though the oxygen vacancy concentration increased nominally. This behavior is ascribed to the strong vacancy-vacancy interaction leading to vacancy ordering. The strong interaction is indicated by the formation of ordered-vacancy phases in nitrogen-doped zirconia. Percolation of elongated tetragonal precipitates of lesser nitrogen concentration and thus of higher conductivity explains the conductivity anisotropy observed by microcontact measurements as well as the large effective dielectric constants.

http://dx.doi.org/10.1111/j.1551-2916.2005.00593.x

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05937275