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Structure of Water and Electron Beam Damaged High Temperature Superconductors

Published online by Cambridge University Press:  28 February 2011

J. P. Zhang ,
D. J. Li  and
L. D. Marks
J. P. Zhang
Affiliation:
Materials Research CenterNORTHWESTERN UNIVERSITY, EVANSTON
D. J. Li
Affiliation:
Materials Research CenterNORTHWESTERN UNIVERSITY, EVANSTON
L. D. Marks
Affiliation:
Materials Research CenterNORTHWESTERN UNIVERSITY, EVANSTON
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Abstract

High Resolution electron microscope observations of the effect of water vapour and the electron beam on high temperature superconductors indicate that the effects are very similar. Water vapour leads to the decomposition into a barium compound which in the microscope is barium oxide (presumably barium carbonate in air) which takes the form of whiskers on the surface and the green and brown phases. The electron beam first produces a true surface amorphous phase which on prelonged irradiation develops a barium oxide surface coating. Different from the results of ion beam damage, we have not seen any evidence for preferential formation of the amorphous phase at grain boundaries. These results indicate that as the oxygen content of the material is reduced, the barium cations become more mobile and can therefore diffuse out to the surface.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 99: Symposium AA – High-Temperature Superconductors , 1987 , 965
Copyright
Copyright © Materials Research Society 1988

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References

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