Pyrochlore microdomain formation in fluorite oxides

Journal Article · Thu May 01 04:00:00 EDT 1986 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(86)90253-7· OSTI ID:5336300

van Dijk, M P; Mijlhoff, F C; Burggraaf, A J

The pyrochlore microdomain formation in the fluorite lattice was investigated by means of electron microscope techniques, especially for the system (Tb/sub x/Gd/sub 1-x/)/sub 2/ Zr/sub 2/O/sub 7+y/ (0 less than or equal to x less than or equal to 1; 0 less than or equal to y < 0.25). Specimens with x > 0.2 or specimens with x less than or equal to 0.2 which were quenched from temperatures above the order-disorder transition temperature show diffuse scattering in the electron diffraction images, remarkably similar to diffuse scattering observed for other defect fluorite oxides. The diffuse scattering is discussed in terms of the formation of a small basic cluster in the fluorite lattice. Annealed specimens with x less than or equal to 0.2 show pyrochlore diffraction spots and microdomain formation. The domains have an average diameter ranging from a value smaller than 10 nm for x = 0.2 up to 100 nm for Gd/sub 2/Zr/sub 2/O/sub 7/. The domains grow in a disordered (fluorite) matrix and finally form antiphase boundaries. The transition from the basic cluster to a well-developed microdomain is not yet clear. The observed microdomain structure is used to explain the results of oxygen ion conductivity experiments.

• Research Organization: Twente Univ. of Technology, AE Enschede, Netherlands
• OSTI ID: 5336300
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 62:3; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
&amp; Refractories-- Structure &amp; Phase Studies
ALLOYS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
DOMAIN STRUCTURE
ELECTRON DIFFRACTION
EXPERIMENTAL DATA
GADOLINIUM COMPOUNDS
INFORMATION
NUMERICAL DATA
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
TERBIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
ZIRCONATES
ZIRCONIUM COMPOUNDS