Fundamental characteristics of a magnetoresistive sensor using Y 1Ba2Cu3O7-x ceramic superconducting films

The fundamental characteristics of a magnetic sensor fabricated from a Y₁Ba₂Cu₃O_7-x ceramic superconducting film are investigated. The operation principle of the sensor is based on the magnetoresistive properties of the material. The Y₁Ba₂Cu₃O_7-x ceramic film was prepared by the spray pyrolysis method. An element of the magnetic sensor consists of the film patterned to a meander shape. the sensitivity is discussed in connection with the noise measurement of the element. A magnetic field resolution of 2×10^-6 G/(Hz) ^1/2 at 100 Hz was obtained in the 0.1-100 G range. The sensitivity is much higher than that of a conventional semiconductor magnetic sensor. With an AC modulation provided by a magnetic field, phase detection of the magnetic field can be performed using a lock-in amplifier. An improvement in the low-frequency (<1 Hz) magnetic field resolution of about one order of magnitude was obtained using this method