Cubic ZrW(1.75)Mo(0.25)O(8) from a Rietveld refinement based on neutron powder diffraction data.

ABSTRACT: The solid solution in the system Zr-Mo-W-O with composition ZrW(1.75)Mo(0.25)O(8) (zirconium tungsten molybdenum octa-oxide) was prepared by solid-state reactions as a polycrystalline material. Its structure has cubic symmetry (space group P2(1)3) at room temperature. The structure contains a network of corner-sharing ZrO(6) octa-hedra (.3. symmetry) and MO(4) (M = W, Mo) tetra-hedra (.3. symmetry). Along the main threefold axis of the cubic unit cell, the MO(4) tetra-hedra are arranged in pairs forming M(2)O(8) units in which the M1O(4) tetra-hedra have larger distortions in terms of bond distances and angles than the M2O(4) tetra-hedra. These units are disordered over two possible orientations, with the M-O(terminal) vectors pointing to the [111] or [] directions. The reversal of the ori

SUBMITTER: Deng X 

PROVIDER: S-EPMC2977542 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature