Determination of the Superconducting Transition Onset Temperature in Small-Volume Specimens

  • T. F. Ciszek
  • E. Tarsa

Abstract

A technique is described for characterizing the normal-to-superconducting transition in small-volume samples via the Meissner effect. The sample is placed in the inductor coil of an LC circuit that oscillates at a resonant frequency \(f = 1/2\pi \sqrt {LC} \), sustained with the aid of a negative-conductance tunnel diode. As the sample temperature T is lowered through the transition, f and T are monitored. Magnetic flux exclusion from the superconductor (and hence from the coil) decreases L and hence increases f. A plot of f vs. T characterizes the transition. A variety of small samples were characterized by this method, and detection limits were determined for a 4.8-mm-diameter, 60-μH inductor coil. The transition onset temperature could be determined for hulk material with mass ≥ 5 mg, thin single crystals with dimensions ≥ 0.5×0.5×0.08 mm3, mesh #80 powders, and films with area ≥ 4 mm2.

Keywords

Zinc Epoxy Assure Boulder 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    John N. Fox and John U. Trefny, Am. J. Phys. 43(1975) 622.ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • T. F. Ciszek
    • 1
  • E. Tarsa
    • 1
  1. 1.Solar Energy Research InstituteGoldenUSA

Personalised recommendations