Magnetotransport Studies of Bi-Based 2212 and 2223 High Critical Temperature Superconductors

When a magnetic field is superimposed on a superconducting sample the electric and temperature gradients allow one to observe phenomena called excess electrical resistivity, excess thermoelectric power, Nernst effect, and excess magnetothermal conductivity. Interesting parameter values can be obtained on vortex and quasi-particle scatterings in the mixed state of materials. For illustration we examine the case of several Bi-based 2212 and 2223 superconducting ceramics. A new (linear) relationship is found between the Ginzburg–Landau parameter and the vortex viscosity. A discussion is given on a new way to get some information on the order parameter symmetry from such transport properties through the analysis of the temperature-integrated excess quantity field dependence in the mixed state.