Magnetic sensor constructed of a thick BPSCCO film: relationship between magnetic sensitivity and the quenching process

A highly sensitive magnetic sensor composed of a thick Bi-Pb-Sr-Ca-Cu-O (BPSCCO) film, which retained a residual resistance at the boiling point of liquid nitrogen (77.4 K), was fabricated. From experimental results, it was found that the magnetic sensitivity of the sensor increased as the resistivity of the residual resistance decreased. During fabrication, the thick BPSCCO film was sintered using two processes, quenching and sintering processes, by use of an electric furnace. The value of residual resistance was found to be related the sintering time T_p, that is, the time for maintaining a constant temperature of 845°C in the quenching process. The magnetic sensitivity of the thick BPSCCO film magnetic sensor for a T_p value of 5 hours, was about 27%/(10^-4 T) over the magnetic field ranging from -10×10^-4 T to +10×10^-4 T, being about 27 times that of a giant magnetoresistance sensor.