Structural Analysis of a Complex Oxide Eu2Mn2/3Nb4/3O7 with a Pyrochlore-Related Structure


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The complex oxide Eu2Mn2/3Nb4/3O7 structurally characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results of XRD structure analysis shown that the X-ray diffraction profile calculated with monoclinic C2/c model is in a good agreement with the observed X-ray diffraction patterns. In addition to fundamental reflection peaks, super lattice lines could be also assigned with C2/c symmetry. Therefore, it is derived that Eu2Mn2/3Nb4/3O7 phase has not a pyrochlore structure but has a zirconolite-type structure (pyrochlore-related structure) with a C2/c space group. Eu2Mn2/3Nb4/3O7 has two kinds of distorted MO6 octahedra and HTB layers, which deviates from the regular forms. The microstructure of Eu2Mn2/3Nb4/3O7 investigated by TEM also proved the results of XRD structural analysis. It was viewed that HRTEM image of a characteristic twin structure in Eu2Mn2/3Nb4/3O7 which a zirconolite-type structure has.



Materials Science Forum (Volumes 449-452)

Edited by:

S.-G. Kang and T. Kobayashi




G. Chen et al., "Structural Analysis of a Complex Oxide Eu2Mn2/3Nb4/3O7 with a Pyrochlore-Related Structure", Materials Science Forum, Vols. 449-452, pp. 969-972, 2004

Online since:

March 2004




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