Properties of junctions using a-axis oriented Y-Ba-Cu-O films.

使用 a 轴取向 Y-Ba-Cu-O 薄膜的结的特性。

• 批准号: 06650357
• 负责人: KOBAYASHI Tadayuki
• 金额: $ 1.34万
• 依托单位: University of Electro-Communications.
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650357/
• 关键词: High Tc superconductor; Thin film; sputtering; Tunnel junction; 超伝導酸化物薄膜; a軸配向膜

Sandwich type SIN junctions of YBa<@D22@>D2Cu<@D23@>D2Ox(YBCO)/SrTiO<@D23@>D2(STO)/Au and YBCO/PrGaO<@D23@>D2(PGO)/Au were fabricated using a-axis oriented YBCO films under the some conditions using a rf magnetron sputtering with dc voltage biased substrate holder. The differential conductance-voltage(dI/dV-V) curves of junctions with defferent barrier thickness were investigated. The junction showed the tunnel-like behavior, though some junctions showed the curves with pinhole-short-circuits. The junctions had the change in the gradient of differential conductance in the curves at about (]SY.+-。[) 20mV.This change was obviously observed with decreasing the barrier thickness. On the other hand, it was also observed the small zero bias anomalies for the junctions with thin barrier. The curves of junctions with PGO barrier were simillar to those with the STO barrier. It is considered that the tunneling occurs via thin region in the ununiform barrier.And then, the effects of dI/dV-V curves on the heat treatment in oxygen gas were also investigated. In order to obtain the change in the gradient of dI/dV in the dI/dV-V curve, the optimum annealing time was 2-4h. The slope of the background conductance of junctions becomes steep with increasing the annealing time.

采用直流偏压衬底保持器和射频磁控溅射技术，在一定条件下制备了YBa<@D22 @>D2Cu<@D23 @> D2 Ox（YBCO）/SrTiO<@D23 @>D2（STO）/Au和YBCO/PrGaO<@D23@>D2（PGO）/Au三明治结构SIN结。研究了不同势垒厚度的结的微分电导-电压（dI/dV-V）曲线。结表现出类似隧道的行为，但有些结表现出针孔短路的曲线。在（]SY. ±-.随着势垒厚度的减小，这种变化明显。另一方面，也观察到了小的零偏置异常的结与薄势垒。有PGO势垒的结的曲线与有STO势垒的结的曲线相似。认为隧穿是通过非均匀势垒中的薄区发生的，并研究了在氧气中热处理对dI/dV-V曲线的影响。为了获得dI/dV-V曲线中dI/dV梯度的变化，最佳退火时间为2- 4 h。随着退火时间的增加，结的背景电导的斜率变陡。