Eddy Current Sensing of Oxygen Content in High-Tc Superconductors
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.
KeywordsBulk Diffusion Silicon Sample Eddy Current Loss Defense Advance Research Project Agency Sensor Impedance
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