A CIRCUIT AND 5 PROBE RESISTIVITY METHOD FOR MEASURING PULSE IV CHARACTERISTICS OF SUPERCONDUCTORS

An electronic circuit has been developed to study the pulse I-V charac teristics of superconductors. A special feature of the circuit is its low rms noise voltage of less than 10 nV, which allows measurements ov er a broad voltage range of 50 nV to 500 mV for the first time. In ord er to overcome the limitations of a four probe technique at high commo n mode voltages, a novel five probe geometry is developed. The measure ments on single crystals of the Bi2Sr2CaCu2Ox superconductor are carri ed out to demonstrate the circuit performance.