YBaCuO和Bi(Pb)SrCaCuO高T_cRF—SQUID

HIGH Tc RF-SQUID OF YBaCuO AND Bi (Pb) SrCaCuO

本文介绍用YBa_2Cu_3O_(7-δ)和Bi_(2-x)Pb_xSr_2Ca_2Cu_3O_y超导体材料制备的RF—SQUID,其最好结果是从高密度YBCO材料的SQUID中得到的。它具有较大的晶粒和较小的临界电流密度,在77K时其磁通噪声大约是6—7×10^(-4)Φ_0/Hz^(1/2) PbBiSrCaCuO体材制备的RF—SQUID观察到了高达10μV的三角波幅度,同时观察到多周期和不规则的频率现象,而且稳定性不理想,经过数次热循环后现象消失。

The RF high Tc SQUIDs have been fabricated from bulk materials of YBaCuO and Bi(Pb)SrCaCuO . The best results were obtained from a high density ceramic which is very homogeneous, with larger grains and smaller critical current.The flux noise of the order of 6-7×10-4Hz^(1/2) was obtained at 77K in the white region. As high as 10V of triangular pattern was measured on the RF SQUID of Bi(Pb)SrCaCuO, and the multi-period was observed with a instability. After several cycles the SQUID pattern was vanished.