Measurement of resistivity and thermopower of superconducting materials in the normal state

A superconductor shows vanishing resistance below a characteristic temperature called the transition temperature Tc. A study of the resistive behavior and thermopower above Tc (i.e., in the normal state) of the superconductor gives valuable information on the nature of the charge carriers and interactions responsible for their scattering. In this paper the authors describe in some detail the techniques used in the measurement of these properties. It is presumed that the materials are available in the form of sintered pellets which is true of the high Tc superconductors. No attempt will be made to give an exhaustive survey of all the techniques available in the literature. The experimental set-up described here will be the one used at IIT, Madras, for many years to measure the above properties