Demonstration experiments for solid-state physics using a table-top mechanical Stirling refrigerator

Abstract

Liquid free cryogenic devices are acquiring importance in basic science and engineering. But they can also lead to improvements in teaching low temperature an solid state physics to graduate students and specialists. Most of the devices are relatively expensive, but small sized equipment is slowly becoming available. Here, we have designed several simple experiments which can be performed using a small Stirling refrigerator. We discuss the measurement of the critical current and temperature of a bulk YBa 2 Cu 3 O 7−δ (YBCO) sample, the observation of the levitation of a magnet over a YBCO disk when cooled below the critical temperature and the observation of a phase transition using ac calorimetry. The equipment can be easily handled by students, and also used to teach the principles of liquid free cooling.

Materials for teaching the rotational motion of magnetically levitating bodies with a video camera

“…Such interesting motions are not only enjoyable to watch but also have the potential to be used in physics education [11][12][13][14]. In particular, the educational use of superconductors has been actively carried out [15][16][17][18][19][20][21][22].…”