Magnetic and Low DC Field Sensing Analysis of Cobalt-Doped YBCO Superconductors as the Core of Fluxgate-Type Sensors

In this study, the critical factors affecting the sensitivity of a magnetic field sensor, based on linear DC field dependence of second harmonic signals generated by co-application of AC and DC fields to polycrystalline type II superconductors, were handled. For this purpose, the Y-123 superconducting samples with different amounts of cobalt ion, as a core material, were synthesized in order to get the best sensing performance. From the M-T and M-H measurements, we have tried to understand the relation between the 2f signal strength (used as the sensor signal) and the characteristic magnetic properties of these superconductors, such as the T-c (on), the T-c (off), and the H-clg. Finally, we could achieve to sense 0.5 mu Oe DC fields by using the Y-123 sample doped with 0.06 wt% of cobalt.