A high Tc superconducting magnetic shield for cryo-electronic devices

The performance of cryo-electronic devices is adversely affected by external magnetic interference and noise. This problem can, however, be eliminated by putting the device in a superconducting shield. Conventional shield materials have an intrinsic noise problem and operate at liquid helium temperature. In this paper we report on a new high Tc shield material, namely Y1Ba2(Cu1−xPbx)3S3xOy (YBCO-PbS) superconductors. This material has been better mechanical properties, these properties being a function of doping. A maximum improvement of three to four times in the mechanical properties was observed for materials having Tc well above liquid nitrogen temperature. The critical magnetic fields that can be shielded fully using cylinders of these materials were found to be 30%–40% higher than those shielded by pure YBCO.