Study of DyBaCuO DC SQUIDs for low noise and high flux focusing

Abstract

Abstrucf ---We have fabricat.ed DyBaCuO DC SQUIDs by MBE growth on MgO substrates containing 45" step-edge Josephson junctions. T h e y s h o w e d R S J -l i k e c u r r e n t -V o l t a g e characteristics and periodic modulation of Voltage aroused by an applied magnetic field at 77K. The flux resolution of the 1.9"square washer SQUID was measured to 3~1 0 -~ @ o / H z " 2 at lHz, which corresponds to a magnetic field sensitivity of 1 4 p T / H z 1 " . Effective flux capture areas were investigated for varying SQUID size of washer and hole.