Nonsuperconducting phases at grain boundaries in YBa/sub 2/Cu/sub 3/O/sub x/ superconductors
The morphology, composition and phases of grain boundaries in YBa/sub 2/Cu/sub 3/O/sub x/ superconductors have been investigated by SEM, TEM and AES. The results show that some impure phase particles present at the grain boundary in the samples sintered at 940/sup 0/C for 26 hours, which grow to be a shell around the grain as the sintering temperature increases to 970/sup 0/C. No such particle has been found at the grain boundaries in the sample sintered at 920/sup 0/C for 26 hours by SEM, J/sub c/ is the highest in our studied samples. AES and TEM analyses indicate that the grain boundaries are complex multilayer structures consisting of barium-rich, copper-rich, carbon-rich, yttrium and oxygen-deficient impure phases. The dominant impure phases harmful to J/sub c/ at the boundary are the mixtures of BaCO/sub 3/, Cu/sub 2/O,BaC/sub 2/, Y/sub 2/C/sub 3/ and an amorphous material.
- Research Organization:
- Baoji Institute for Non-ferrous Metal Research, P.O. Box 71, Baoji, Shaanxi (CN)
- OSTI ID:
- 5764009
- Journal Information:
- Int. J. Mod. Phys. B; (United States), Journal Name: Int. J. Mod. Phys. B; (United States) Vol. 3:3; ISSN IJPBE
- Country of Publication:
- United States
- Language:
- English
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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
AMORPHOUS STATE
AUGER ELECTRON SPECTROSCOPY
BARIUM CARBONATES
BARIUM COMPOUNDS
BARIUM OXIDES
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMICAL COMPOSITION
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
FABRICATION
GRAIN BOUNDARIES
IMPURITIES
MICROSCOPY
MICROSTRUCTURE
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHASE STUDIES
PHYSICAL PROPERTIES
SCANNING ELECTRON MICROSCOPY
SINTERING
SPECTROSCOPY
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
YTTRIUM COMPOUNDS
YTTRIUM OXIDES