Tunneling Spectroscopy of PCCO

A point-contact probe capable of operating down to temperatures of 1.5 K and in magnetic fields of up to 32 T was designed and constructed. With this probe, preliminary data was obtained on Pr2-xCexCuO4 (PCCO) which reproduced previously published data in fields up to 8 T and temperatures down to 4.2 K. What is a superconductor? A material that can carry current without resistance at temperatures below some critical temperature (Tc) is a superconductor. A related property of materials in the superconducting state (below Tc) is their ability to obstruct magnetic fields from entering them (Meissner Effect). However, at a high enough magnetic field (critical field or Hc), field lines can enter the material. The critical field depends on the Tc of the material (kTc~μBHc) and also increases with decreasing temperature. Different varieties of superconductors exist including conventional (those that follow the BCS model) and high Tc materials. In addition, there are type I superconductors that go normal as soon as the magnetic field is able to penetrate and type II superconductors that continue to superconduct as field lines penetrate the material (at Hc1) until the applied field reaches