Research on SIS nanoarray-type high-frequency mixer using Bi-2212 single crystals

Bi-2212单晶SIS纳米阵列型高频混频器的研究

基本信息

批准号：
15560040
负责人：
HAMASAKI Katsuyoshi
金额：
$ 2.37万
依托单位：
Nagaoka University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

High-quality Bi_2Sr_2CaCu_2O_<8+δ>(Bi-2212) single crystals were grown by a self-flux method without mixing and grinding of reagent starting powders. During the crystal growth process, a pressure (<0.4 N/cm^2) was applied using a brick placed on the cap on an alumina crucible. We obtained high-quality single crystals with zero-resistance transition temperature, T_<c,zero>【approximately equal】89K, with this techniques. We also developed new fabrication process of stacked intrinsic Josephson junctions using Bi-2212 crystals. For the planarization of the stacks, the crystal around the junction window was modified to insulating layer by dipping into the solution of hydrochloric acid. For the concentration is lower than 0.1%, the planarization of the stack was fully achieved. For the concentration is higher than 0.5%, however, the planarization was spoiled. The number of intrinsic junctions in the stack linearly increased with increasing the concentration in the range from 0.05 to 0.2%. The … More thickness of the acid-treated layer can be evaluated by the number of the branches in I-V curve. This well controlabillity of the number of the junctions in the planarized stacks is useful for the electronics applications, such as high-frequency mixer. The current-voltage (I-V) characteristics of the stacks were uniform and observed distinct resistive branches with large hysteresis even at 77K, which can be explained by a series connection of highly capacitive Josephson junctions. At higher temperatures than 40K, we found that the return current Ir of the intrinsic junction depended strongly on the temperature, T. We analyzed the Ir-T characteristics using simple resistively and capacitively shunted junction (RCSJ) model in view of the temperature dependence of the c-axis resistance of the stack. The Ir-T characteristics were found to be well explained by the Zappe theory based on the RCSJ model. The present results may be useful information for a better understanding of the Bi-2212 intrinsic Josephson characteristics. Less

高质量的BI_2SR_2CACU_2O_ <8+δ>（BI-2212）单晶是通过自升方法生长的，而无需混合和研磨试剂启动粉末。在晶体生长过程中，使用放置在氧化铝坩埚上的盖上的砖块施加压力（<0.4 n/cm^2）。我们获得了具有零抗性转变温度的高质量单晶，T_ <C，零>【大约等于89k，使用此技术。我们还开发了使用BI-2212晶体堆叠固有的约瑟夫森连接的新制造过程。对于堆栈的平面化，通过浸入盐酸的溶液中，修改了连接窗口周围的晶体以绝缘层。对于浓度低于0.1％，堆栈的平面化已完全实现。但是，对于浓度高于0.5％，但是，平面化被宠坏了。堆栈中的固有连接数量随着浓度在0.05至0.2％的增加而增加。 …可以通过I-V曲线中的分支数来评估酸处理层的厚度。计划堆栈中连接数量的这种井的可控性对于电子应用（例如高频混合器）很有用。堆栈的电流 - 电压（I-V）特性是均匀的，甚至在77K处观察到具有较大磁滞的独特抗性分支，这可以通过一系列高电容性的Josephson连接来解释。在高于40K的温度下，我们发现固有连接的回流电流IR依赖于温度，T。我们使用简单且一致分流的连接（RCSJ）模型分析了IR-T特性，从而观察到堆栈的C轴电阻的温度依赖性。根据RCSJ模型，发现IR-T特征通过Zappe理论很好地解释了。目前的结果可能是有用的信息，可以更好地了解BI-2212内在的约瑟夫森特征。较少的