Characteristics of a Bulk High-Critical Temperature Superconductor Fabricated by the Shock Compaction Method: Possible Use as a Highly Sensitive Magnetic Sensor

A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O (BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm2 in the absence of an excitation magnetic field Bex. The superconducting state was then broken and the specimen exposed to a Bex value of 40x10-4 T. That is, the resistance Rmeas of the specimen occurred when exposed to 40x10-4 T under a constant J of 40 A/cm2. The magnetic sensitivity S of the specimen was approximately 13 %/(10-4 T) over the range of measurement of the magnetic field Bmeas from 0 to ±5x10-4 T, under a constant 40x10-4 T for the value of Bex, being approximately 13 times greater than that of a giant magnetoresistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor