APPLICATION OF THE HALL-PROBE TECHNIQUE FOR MAGNETIZATION MEASUREMENTS OF SUPERCONDUCTORS

A commercial Hall probe (supplied by Lake Shore Cryotronics, Inc.) is used as a sensor of the magnetic field at the surface of a magnetized sample. With the Linear Research resistance bridge LR400, an excellent stability, linearity of response on field and an extremely small temp erature dependence of the background signal is obtained, which is esse ntial for this kind of applications of a Hall probe. At certain condit ions, a resolution in field measurements of about 10 mG is reached. Ex amples of magnetization measurements as a function of temperature, mag netic field and time, performed on high-T(c) and heavy-fermion superco nductors, are discussed.