Distribution of the M-M distances in the rare earth oxides

Authors
Citation
A. Vegas et R. Isea, Distribution of the M-M distances in the rare earth oxides, ACT CRYST B, 54, 1998, pp. 732-740
Citations number
48
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE
ISSN journal
01087681 → ACNP
Volume
54
Year of publication
1998
Part
6
Pages
732 - 740
Database
ISI
SICI code
0108-7681(199812)54:<732:DOTMDI>2.0.ZU;2-J
Abstract
A systematic study of the distribution of the M-M distances in all the bina ry, ternary and quaternary oxides of the rare earth elements (RE = Sc, Y, L a-Lu), contained in the Inorganic Crystal Structure Database (ICSD) has bee n carried out. The results indicate that the RE-RE distances are not distri buted uniformly, but present maxima which are close to the corresponding di stances in the pure metals. In some of the histograms (Y, Ce, Pr, Sm, Tb, D y, Ho, Lu) two maxima appear which correspond to the nearest-neighbor (b.c. c., h.c.p.) and second-nearest neighbor (b.c.c.) distances of the elemental phases. As examples of this behavior, the cation arrays of the binary oxid es, hydroxides and ternary oxides of both the delafossite and alpha-NaFeO2 type are analyzed. In all of them the cations form aggregates whose topolog ies and distances can be related to the structure of the parent metals. The size of the metal aggregates seems to decrease with increasing oxygen cont ent.