Corrosion and Passivation of High Temperature Superconductors
Final rept. 1 Jul 88-30 Sep 90,
STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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Silver and copper were deposited by electroless deposition upon YBa2Cu3O7 bulk pieces and fibers. The electrical properties of these coated materials were determined by the four-point resistivity method. Good electrical contact between electroless silver layers and the YBa2Cu3O7 substrate could be attained. Copper was electrodeposited on electroless silver layer provided excellent environment protection to the underlying YBa2Cu3O7. The stability of YBa2Cu3O6.5x powder in various aqueous and nonaqueous environments was studied. The time dependence of sample weight and oxygen content, x, were determined for the samples exposed to atmospheres saturated with concentrated ammonium hydroxide, glacial acetic acid, acetone, hexane, toluene, ethanol and methanol. Little evidence for reaction was found for the latter five organic vapors, while substantial reaction was found for the first two vapors. YBa2Cu3O6.5x powder was also suspended in deionized water and aqueous 1 molar solutions of NaCl, KCl, KNO3, and NaBr. The results suggest that reaction is minimal and probably involves only the surface of the powder.
- Inorganic Chemistry
- Physical Chemistry
- Electricity and Magnetism