Autor: |
Seminozhenko, V P, Zagoskin, V T, Litvinenko, Yu G, Moghilko, E T, Poltoratskii, Yu B, Tuchin, O V |
Zdroj: |
Bulletin of Materials Science; April 1991, Vol. 14 Issue: 2 p179-183, 5p |
Abstrakt: |
Effect of water vapour on the YBa2Cu3O7−xceramics of different density has been studied using Auger electron and X-ray photoelectron spectroscopy. The initial period of decomposition of this compound when exposed to H2O is accompanied by Ba(OH)2deposition on the ceramic grain surface and partial reduction of copper to Cu2O in the oxide. With this barium diffuses to free surfaces of ceramic grains. Degradation of HTSC ceramics proceeds by increase of thickness of the changed layer on free surfaces of grains. Violation of the initial composition may at first lead to some improvement of transitional characteristicsTcand ΔTcand with their subsequent degradation, the transition width ΔTcis in particular broadened. Dense ceramics possess higher resistance to a humid atmosphere. |
Databáze: |
Supplemental Index |
Externí odkaz: |
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