Design And Characterization Of A YBa2Cu3O7-´ dc-Superconducting Quantum Interference Device For Magnetic Microscopy

A dc-SQUID (Superconducting Quantum Interference Device) based magnetometer for magnetic microscopy applications has been designed and tested. A square loop has been chosen as pick-up coil and a direct coupling configuration with the SQUID has been realized. On this scale dimension, the strips connecting SQUID and pick-up coil induce a non-negligible effect on the device performances. In particular, a reduction of the effective area is predicted. A SQUID device has been fabricated on symmetric 30° [001]-tilt YBa2Cu3O7-x bicrystal and its behavior has been tested. Characterization results in terms of current-voltage characteristics and magnetic field response are reported. They well agree with expected behaviors. Moreover, magnetometer response to a localized magnetic field has also been investigated.