Electrical Properties of Superconductors

Abstract

Exploring electrical properties of superconductors using four-lead resistance measurements.

A sketch of the device
A sketch of the device

Portable

Yes – with some effort

Principles Illustrated

In a series of experiments designed for year 13 physics and/or tertiary students we explore the drop in resistance to zero at the critical temperature. We sometimes show students how to automate the measurement in a programming language called LabVIEW.

A superconducting magnet.  NMR lab, Victoria University
A superconducting magnet.
NMR lab, Victoria University
A four-lead resistance measurement  of a high temperature superconducting wire  at HTS-110 in Lower Hutt.
A four-lead resistance measurement
of a high temperature superconducting wire
at HTS-110 in Lower Hutt.

NCEA & Science Curriculum

PHYS 1.3, PHYS 2.6

Instructions

Schematic of the apparatus
Schematic of the apparatus

The superconductor is immersed in sand after connection to a power supply and a voltmeter set up for four-lead resistance measurements. A thermocouple is used to measure temperature. The apparatus is cooled with liquid nitrogen and warms slowly while students take data. See Detailed Instructions for more information.

Safety

If you do not have training and confidence in the use of liquid nitrogen, contact a university physics or chemistry department for help. In any case, follow the usual liquid nitrogen precautions including goggles. In addition, a high ratio of demonstrators to students is strongly recommended.

Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.

Related Resources

Floating on Air

Teaching Resources

Would you like to contribute lesson suggestions? Contact us.

References

We have a classroom set of these devices purchased from Colorado Superconductor.

Credits

This teaching resource was developed with support from

The MacDiarmid Institute
Faculty of Science, Victoria University of Wellington
School of Chemical and Physical Sciences, Victoria University of Wellington

Copyright

Copyright and fair use statement