Low 1/f flux noise in sputtered YBa2Cu3O7-x bicrystal dc-superconducting quantum interference devices

A low 1/f flux noise YBa2Cu3O7-x bicrystal dc-superconducting quantum interference device was fabricated using the cylindrical magnetron sputtering method. The experimental values of the magnetic flux-to-voltage transfer parameter obtained were lower than expected. Using wide band reversal electronics, the 1/f noise levels were reduced. Single large magnetometers working at 77 K were also assembled, where a relatively high value of the flux to field transfer factors was achieved.