Properties of DC SQUIDs Made from YBCO and TBCCO Films

Double-microbridge dc superconducting quant um interference devices(SQUIDs) have been fabricated from the postannealed Y₁Ba₂Cu₃O_y and T1₂Ba₂Ca₂Cu₃O_y, thin films by chemical etching and ion milling patterning technique. The applied magnetic field dependences of the voltage of the YBCO and TBCCO SQUIDS have been studied at temperature ranging from 4.2 to 23K and at 77K. The largest output voltage of the devices were 3.4,μV/Ф₀ (at 5 K ) for YBCO and 60μV/Ф₀(at 77K) for TBCCO. The properties of the output of these devices have been discussed.