Determining Superconductor Inhomogeneity at Room Temperature

A technique for determining inhomogeneities in a specimen of a high-critical-temperature superconductor involves scanning a small eddy-current probe over a flat surface of the specimen at room temperature while monitoring the inductance of the probe. In contrast, older techniques for obtaining the same or similar information involve cooling the specimen below its superconducting-transition critical temperature (TC), with attendant difficulty and cost of operating a cryogenic apparatus.