From fluorite to pyrochlore: Characterisation of local and average structure of neodymium zirconate, Nd2Zr2O7

• The first total scattering and RMC modelling study of Nd2Zr2O7.
• Demonstration that the synthetic route influences the crystal structure adopted.
• Insight into the importance of total scattering in studies of complex superstructures, especially for nano-sized materials.

The structural characterisation of Nd2Zr2O7 prepared via a precursor route was performed using a combination of local and average structure probes (neutron total scattering, X-ray and neutron diffraction). We present the first total scattering and reverse Monte Carlo (RMC) modelling study of Nd2Zr2O7, which provides compelling evidence for the adoption of a disordered fluorite-type structure by Nd2Zr2O7 prepared by a low-temperature precursor route. Annealing the material at high temperatures leads to a transformation to a pyrochlore-type structure; however, Rietveld refinement using powder neutron diffraction data shows that the oxygen sublattice retains a degree of disorder.

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