We will use samples of materials that are superconducting at liquid nitrogen temperature. Measure the resistance as a function of temperature to observe the onset of superconductivity, and compare your value to the published critical temperature. Also observe the Meissner effect, which is the levitation of a magnet above a superconductor. Compare the height of the magnet to the theoretical value.
Optional: try to make your own superconductor in our furnace, which is equipped with an Omega programmable temperature controller.
You will be introduced to some techniques of condensed matter physics: 4-point resistance measurement, cryostat design, and LN2 handling. This experiment emphasizes constructing or modifying the apparatus yourself.
