https://doi.org/10.1051/epjap:2000192
A neutron diffraction study of BaCexZr1−xO3
1
Laboratoire d'Electrochimie et de Physicochimie des Matériaux et Interfaces (UMR INPG-CNRS),
ENSEEG B.P. 75,
38402 Saint Martin d'Hères, France
2
Institut Laue Langevin, Chemin des Martyrs, 38000 Grenoble, France
Corresponding author: Thierry.Pagnier@lepmi.inpg.fr
Received:
6
May
1999
Revised:
17
September
1999
Accepted:
20
October
1999
Published online: 15 January 2000
High resolution neutron diffraction patterns of BaCexZr1−xO3 (x = 0, 0.1, 0.4,
0.8) were obtained at various temperatures. The phase diagram that was deduced from Raman
measurements has been confirmed. Structural transitions occur in a fixed order
Pnma-Imma- R
c-Pm3m as a function of temperature or composition. For BaCeO3, the
large volume change that has been previously claimed at the Imma-Rc transition has
been revisited and found inconsistent. For a given composition, the cell volume increases
when temperature increases, but the MO6 (M=Ce-Zr) octahedron volume decreases. It is
shown that the ratio of the cell volume to the octahedron volume is a good indicator of the
phase transitions. Transitions occur at fixed values (5.77, 5.80 and 6 for the Pnma-Imma,
Imma-Rc and Rc-Pm3m transitions respectively) independently of
composition.
PACS: 61.12.Ld – Single-crystal and powder diffraction / 64.70.Kb – Solid-solid transitions
© EDP Sciences, 2000
