High Tc TMR-Superconducting Mixed Sensor: Fabrication and Performance

Giant magneto-resistive (GMR)-superconducting mixed magnetic sensors are expected to be widely used because of their excellent sensitivity, stability, band characteristics, and low cost. If a tunnel magnetoresistance (TMR)-superconducting mixed magnetic sensor is prepared using a higher sensitivity and lower power TMR instead of GMR, the performance of the device will be further improved. We have fabricated a TMR-superconducting mixed sensor by a bonding process, and the feasibility was verified. The sensitivity was 21 times higher than that of the TMR device alone, reaching 18.1%/Oe. The noise level reached 6.6 pT/Hz
^1/2
at 77 K. At the same time, the influence of different constriction width of the superconducting magnetic flux concentrator on the device performance was compared at 4.5–77 K.