Self-diffusion of Hf in Er/sub 2/O/sub 3/-doped polycrystalline HfO/sub 2/

Technical Report · Thu Oct 01 04:00:00 EDT 1981

OSTI ID:5677637

Tesch, R J

Volume self-diffusion coefficients for Hf were measured in polycrystalline erbia-doped hafnia over a compositional range of 10 to 40 m/o erbia, in air at temperatures of 1967, 1900, and 1700/sup 0/C and at a P/sub O/sub 2// of <10/sup -7/ atm at temperatures of 2033 and 1818/sup 0/C, using a tracer serial sectioning technique. The compositional dependence was small, indicating the possibility of several competing diffusional jump mechanisms as well as the clustering of defects and the possible presence of very defective micro-domains. The activation energy for diffusion decreased from 185 +- 7 kcal/mole to 153 +- 9 kcal/mol between 10 and 40 m/o Er/sub 2/O/sub 3/. In cases where grain boundary diffusion coefficients could be determined, they were about 10/sup 4/ times the volume diffusion coefficients. Results were compared to those of cation diffusion in the analogous CaO-ZrO/sub 2/ system.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5677637
• Report Number(s): IS-T-953; ON: DE82005580
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
ACTIVATION ENERGY
ATOM TRANSPORT
CHALCOGENIDES
DIFFUSION
DOPED MATERIALS
ELEMENTS
ENERGY
ERBIUM COMPOUNDS
ERBIUM OXIDES
HAFNIUM
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
MATERIALS
METALS
NEUTRAL-PARTICLE TRANSPORT
OXIDES
OXYGEN COMPOUNDS
QUANTITY RATIO
RADIATION TRANSPORT
RARE EARTH COMPOUNDS
REFRACTORY METALS
SELF-DIFFUSION
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE