The defect structure of Y- and N-doped zirconia

The diffuse scattering of a single crystal of the quaternary system Zr-Y-O-N (Zr_0.96Y_0.04O_1.64N_0.223) has been recorded by neutron diffraction in different layers of the [10] and [100] zones to study the short-range order originating from anion vacancies. A new model is proposed with uncorrelated anion vacancies and radial shifts of the surrounding ions towards or away from the vacancies. The parameters of the model were refined by fitting to the diffuse scattering intensities. The shortest Zr-anion distance is reduced, indicating covalent contributions.