Transport critical current measurement apparatus using liquid nitrogen cooled high-T(c) superconducting magnet with...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Superconductivity

Background:

• High-temperature superconductors (high-T(c)) require precise characterization of their transport critical current (I(c)).
• Existing measurement techniques often involve complex cryogenic systems.
• Developing accessible methods for I(c) measurements under varying magnetic fields and temperatures is crucial.

Purpose of the Study:

• To design and demonstrate an apparatus for I(c) measurements of high-T(c) superconductors.
• To utilize liquid nitrogen as the sole cryogenic medium.
• To achieve stable measurements at magnetic fields up to 1 Tesla and temperatures between 66-88 K.

Main Methods:

• An apparatus was constructed using a (Bi,Pb)(2)Sr(2)Ca(2)Cu(3)O(10) (Bi-2223) superconducting magnet and a variable temperature insert (VTI).
• The system operates entirely with liquid nitrogen, with the magnet at depressurized conditions and the sample immersed.
• The VTI pressure was controlled between 0.02 to 0.3 MPa to achieve temperatures from 66 to 88 K.

Main Results:

• The Bi-2223 magnet demonstrated stable operation at 1 Tesla.
• The apparatus successfully maintained temperature stability for the sample under high transport currents.
• The system facilitates easy operation for I(c) measurements up to 500 A.

Conclusions:

• A novel, user-friendly apparatus for I(c) measurements of high-T(c) superconductors has been successfully developed.
• The apparatus leverages liquid nitrogen for operation, simplifying cryogenic requirements.
• This system enables reliable characterization of superconductors in relevant magnetic fields and temperature ranges.