Ba_(1-x)K_xBiO_3(BKBO)氧化物超导体的发现,引起了人们浓厚的兴趣.高温超导体,如YBCO,呈各向异性的电学性质,相干长度ζ较短(ab)平面相干长度约为1.2～1.5nm,c方向相干长度约为0.2～0.3 nm),较难制备出在超导电子学上有重要应用的SIS型隧道结.而BKBO是一立方晶体超导体,具备各向同性的电学性质,并且相干长度较长,约为5～7nm,有可能制备出性能优良的SIS型隧道结.Fink等人制备了滞后的YBCO/SrTiO_3/BKBOJosephson结,并观察到了Shapiro台阶和自感应台阶.BKBK/I/BKBO型结构也相继发表, The discovery of Ba_ (1-x) K_xBiO_3 (BKBO) oxide superconductors has aroused great interest.High-temperature superconductors, such as YBCO, have anisotropic electrical properties and the coherence length ζ has shorter 1.2 ~ 1.5nm, c-direction coherence length of about 0.2 ~ 0.3nm), it is difficult to prepare an important application in the superconductivity of SIS tunnel junctions .BKBO is a cubic crystal superconductor, with isotropic electrical Properties, and the coherence length is longer, about 5 ~ 7nm, it is possible to prepare a good performance SIS tunnel junction.Fink et al prepared a lag YBCO / SrTiO_3 / BKBOJosephson junction, and observed Shapiro steps and self-sensing step. BKBK / I / BKBO type structure has also been published,