权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fabrication of High-Tc Superconducting Co-planar Josephson Junctions Using Focused Ion Beam

使用聚焦离子束制造高温超导共面约瑟夫森结

基本信息

批准号：
07455147
负责人：
OKABE Yoichi
金额：
$ 4.03万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

YBaCuOco-planar junctions were fabricated using Focused Ion Beam (FIB) . A YBaCuO has two-dimentional conductivity of super-current. The co-planar junction has the most effective current flow in the YBaCuO Junctions. We have been fabricated two types of the co-planar junctions using FIB (One is the colally damaged substrate type. The other is the locally ion irradiate type) .YBaCuO co-planar Josephson junctions with the abnormally grown YBaCuO were produed using Focused Ion Beam. FIB was used to form a narrow region of ion damage on the MgO (100) substrate.The junctions were fabricated by changing the thickness of a YBaCuO thin film. The junctions had the thickness dependence of the characterstics. From the observation of the junction surface, the junction length was decreased with increasing film thickness by the horizontal growth of the normally grown YBaCuO in the thinner film junctions. It is considered that the Jeosephson current for the thicker film junctions flows dominantly in the microshorts, and Josephson current for the thinner film junctions flows in the abnormally grown YBaCuO area.Josephson junctions were fabricated by irradiating Be ions on a YBaCuO thin film with FIB.The junctions had the I-V curve of RSJ,the IcRn product from 0.6mV to 2.0mV,and a good magnetic response at 4.2K.The critical current density of the junctions decreased exponentially with increasing the ion fluence. From the estimation of the damage distrubution, the junction length increased with the ion fluence. The damaged YBaCuO thin film showed the characteristic of the normal metal. Therefore, it is considered that the junctions had the SNS type junction with a proximity effect. When the junctions which were fabricated six mounth ago were measured, the current distribution of the junction did not changed. The junction stability was good.

YBaCuO共平面结是使用聚焦离子束（FIB）制造的。 YBaCuO具有超电流的二维导电性。在 YBaCuO 结中，共面结具有最有效的电流。我们已经使用FIB制造了两种类型的共面结（一种是共损伤衬底型。另一种是局部离子辐照型）。使用聚焦离子束生产了具有异常生长的YBaCuO的YBaCuO共面约瑟夫森结。使用 FIB 在 MgO (100) 基板上形成狭窄的离子损伤区域。通过改变 YBaCuO 薄膜的厚度来制造结。结点具有厚度依赖性的特性。从结面的观察来看，结长随着膜厚的增加而减小，这是由于在较薄的膜结中正常生长的YBaCuO水平生长造成的。认为厚膜结的约瑟夫森电流主要在微短路中流动，而薄膜结的约瑟夫森电流主要在异常生长的YBaCuO区域中流动。约瑟夫森结是通过用FIB在YBaCuO薄膜上照射Be离子来制造的。该结具有RSJ的I-V曲线，IcRn乘积从0.6mV到0.6mV。 2.0mV，在4.2K时有良好的磁响应。结的临界电流密度随着离子注量的增加呈指数下降。从损伤分布的估计来看，结长度随着离子注量的增加而增加。受损的YBaCuO薄膜表现出正常金属的特性。因此，认为该结具有具有邻近效应的SNS型结。当测量六个月前制造的结时，结的电流分布没有改变。结稳定性良好。