Deformation of nonstoichiometric CuO polycrystals
The current interest in fabrication methods for high temperature superconductors has fostered heightened interest in the precursor materials. It has been shown that the reaction kinetics for formation of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x}, (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} and YBa{sub 2}Cu{sub 3}O{sub x} are related to the copper oxide precursor through both the size of the starting powder and the oxidation state, with finer CuO powders reacting faster. Many proposed fabrication methods include a high temperature mechanical working step during the reaction process. However, little is known about the diffusional and mechanical properties of CuO at the fabrication temperatures of interest. The literature indicates only that the electrical conductivity of CuO is independent of the oxygen partial pressure (PO{sub 2}). Therefore, only intrinsic ionization occurs for CuO. Thus, for a given temperature, the concentrations of electrons and holes are fixed. In this study, compression creep was employed to shed light upon the diffusion of rate-controlling defects in nonstoichiometric CuO. Tests were performed on polycrystalline samples over a range of temperature (T), PO{sub 2}, and strain rate ({epsilon}). Data were analyzed with standard equations for steady-state creep. Electron microscopy was used in conjunction with the data analysis to identify the operative creep mechanisms. These results for CuO will be contrasted with previous work performed on another copper oxide compound, Cu{sub 2}O.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10175268
- Report Number(s):
- ANL/ET/CP-82163; CONF-940865-2; ON: DE94016907; TRN: 94:007765
- Resource Relation:
- Conference: Conference on plastic deformation of ceramics,Snowbird, UT (United States),7-12 Aug 1994; Other Information: PBD: Jul 1994
- Country of Publication:
- United States
- Language:
- English
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