In this article, we discuss the behavior of high-temperature superconductors and how to demonstrate them safely and effectively in the high school or introductory physics classroom. Included here is a discussion of the most relevant physics topics that can be demonstrated, some safety tips, and a bit of the history of superconductors. In an effort to include first-year physics students in the world of modern physics, a topic as engaging as superconductivity should not be missed. It is an opportunity to inspire students to study physics through the myriad of possible applications that high temperature superconductors hold for the future.
REFERENCES
1.
Dirk
Van Delft
and Peter
Kess
, “The discovery of superconductivity
,” Phys. Today
63
(9
), 38
(2010
).2.
YBCO superconductors have been discussed in this journal before [please see
R.
Brown
, “Demonstrating the Meissner effect and persistent current
,” Phys. Teach.
38
, 168
–169
(March
2000
)]. I hope that my article can provide direction to those who would not know where to begin, and also helps justify their inclusion at the high school level. For a good explanation of theory that explains superconductivity as Cooper pairing, give Cooper’s own article,3.
TED Talk with Boaz Almog, the inventor of this device: https://www.ted.com/talks/boaz_almog_levitates_a_superconductor, in which he demonstrates an early version of it.
4.
Even though it is out of date, I recommend Gavaler’s article,
J. R.
Gavaler
, “The search for better superconductors
,” Phys. Teach.
15
, 289
–291
(May
1977
) because of its excellent figures. Also,E. H.
Brandt
, “Rigid levitation and suspension of high-temperature superconductors by magnets
,” Am. J. Phys.
58
, 43
–49
(Jan.
1990
) discusses flux pinning and differentiates between Type I and Type II superconductors. YBCO is Type II.5.
The probe is a resistor and must be calibrated to serve as a thermometer. For example it has a resistance of 20 Ω at 77 K, which is the boiling temperature of liquid nitrogen.
© 2017 American Association of Physics Teachers.
2017
American Association of Physics Teachers
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