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Eddy Current Sensing of Oxygen Content in High-Tc Superconductors

  • Ward Johnson
  • A. H. Kahn
  • C. K. Chiang
  • H. N. G. Wadley
Chapter
Part of the Review of Progress in Quantitative Nondestructive Evaluation book series

Abstract

The superconducting properties of Ba2YCu3O7-x are strongly dependent on the amount of oxygen contained in the material. Although the physical mechanisms of oxidation have not yet been fully characterized, the reaction rates appear to be influenced by surface adsorption, in addition to bulk diffusion [1,2]. The task of constructing an optimal high-temperature processing schedule is, therefore, complicated by the fact that porosity and surface conditions strongly influence oxidation. An additional complication arises from the fact that, while the diffusion and adsorption rates increase with increasing temperature, the equilibrium oxygen concentration in the material decreases with increasing temperature, so that, after the final annealing, cooling must proceed slowly enough to allow adequate absorption to occur.

Keywords

Bulk Diffusion Silicon Sample Eddy Current Loss Defense Advance Research Project Agency Sensor Impedance 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • Ward Johnson
    • 1
  • A. H. Kahn
    • 1
  • C. K. Chiang
    • 1
  • H. N. G. Wadley
    • 2
  1. 1.National Institute of Standards and TechnologyGaithersburgUSA
  2. 2.University of VirginiaCharlottesvilleUSA

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