Unit cell used to study the properties of bulk . The unit cell contains 4 atoms of Ce, 4 atoms of Zr, 4 atoms of Tb, and 24 atoms of O. The positions of the metal cations were exchanged in the unit cell to reflect a random solid solution (see text). In the figure is shown a possible configuration for the ternary oxide.
Lattice constants determined by x-ray diffraction at for nanoparticles of , , , and . The notation used to label the mixed-metal oxides is explained in Sec. II A.
Cell parameters determined for and nanoparticles from XRD patterns (solid lines) and estimated using Vegard’s rule (Ref. 35) and the experimental lattice parameters for bulk (Ref. 4), (Ref. 34), and (Refs. 4 and 17) (dashed lines).
Cell parameters for nanoparticles obtained from XRD (solid line) and Vegard’s rule (dashed line). In the top panel, the ratio is maintained constant while Zr is added. In the bottom panel, Tb is added keeping the ratio constant.
Strain parameter (obtained from XRD patterns at ) for , , , and nanoparticles.
Raman spectra taken at for a series of nanoparticles.
Time-resolved XRD results obtained after heating a sample of nanoparticles from . Heating , and .
Variation of particle size (top panel) and cell dimension (bottom panel) with temperature for nanoparticles of , (CZ11), (CT11), and (CZT111). Heating .
O -edge XANES spectra taken at room temperature for and nanoparticles. The notation used to label the mixed-metal oxides is explained in Sec. II A. The top panel compares the experimental spectrum (solid trace) for nanoparticles and that obtained by adding the corresponding spectra for , (Ref. 18), and (Ref. 8) weighted by the concentration of the metals in the ternary oxide (dashed line).
Ce -edge XANES spectra for and nanoparticles taken at room temperature.
Room-temperature Zr -edge XANES spectra for monoclinic , , and nanoparticles.
Tb -edge spectra for a reference (probably ) and nanoparticles at .
Calculated Mulliken charges (e)
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