Development of Superhigh-Frequency Electromagnetic-Wave Detectors Using Grain-Boundary Junctions of BKBO

利用 BKBO 晶界结开发超高频电磁波探测器

• 批准号: 07505014
• 负责人: HAYAKAWA Hisao
• 金额: $ 3.26万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07505014/
• 关键词: oxide superconductor; BKBO; thin film; bicrystal; tunnel junction; grain-boundary junction; superhigh frequency; electromagnetic-wave detector; SISミキサ-; 超高周波電磁波検出器; 熱処理

Ba_<1-x>K_xBiO_3(BKBO)grain-boundary junctions fabricated on bicrystal substrates are Josephson tunnel junctions which show the SIS (superconductor-insulator-superconductor) feature. A highly-sensitive sensor for superhigh-frequency electromagnetic-waves is a candidate for the application of these junctions, utilizing the gap energy of BKBO wider than those of metal superconductors. In this research, we intended to develop the SIS mixers for the detection of super high-frequency electromagnetic waves using BKBO grain-boundary junctions, and studies on the use of low-permitivity substrates, the improvement of junction properties and the development of junction integration technology (high-frequency circuits) were carried out.1. Establishment of the technology for the deposition of BKBO thin films on low-permittivity substrates :In order to establish the technology for the deposition of thin films on low-permittivity substrates necessary for high-frequency application, we tried to prepar … More e BKBO thin films on Mg (permittivity : 10). Since the deposition of BKBO thin films of high quality on MgO is more difficult than on SrTiO_3 (STO), we investigated the effect of the substrate treatment, buffer layrs, etc. It was found that the in-situ annealing of the substrate before the deposition in the sputter chamber is effective, and BKBO films which shows properties similar to those on STO were obtained. A buffer BKBO layr deposited at a high substrate temperature for a short time prior to the deposition at the normal temperature for superconducting films gives a (100) BKBO film of high quality on (100) MgO substrate.2. Investigation of junction properties :We investigated the properties of the junctions on STO.The velocity of the electromagnetic wave in the barrier of the junction is an order smaller than that reported for junctions of other materials, which suggests the effect of the high permittivity of the substrate and the necessity of low-permittivity substrates.3. Study of high-frequency circuits :We studied the circuits for the basic experiments of the superhigh-frequency detector including junctions and other components such as antennas, etc. Less

在双晶衬底上制备的BKBO；1-x&gt；K_xBiO_3(BKBO)晶界结是具有超导-绝缘体-超导体(SIS)特性的约瑟夫森隧道结。一种高灵敏度的超高频电磁波传感器是这些结应用的候选者，它利用了BKBO比金属超导体更宽的能隙。在本研究中，我们打算利用BKBO晶界结开发用于探测超高频电磁波的SIS混频器，并对低介电系数衬底的使用、结性能的改善以及结集成技术(高频电路)的发展进行了研究。低介电常数衬底上沉积BKBO薄膜工艺的建立：为了建立高频应用所必需的低介电常数衬底上沉积薄膜的工艺，我们尝试制备了…在Mg(介电常数：10)上制备了更多的e-BKBO薄膜。由于在MgO衬底上沉积高质量的BKBO薄膜比在SrTiO_3(STO)衬底上沉积高质量的BKBO薄膜更困难，我们研究了衬底处理、缓冲层等因素的影响，发现衬底在溅射室中沉积之前的原位退火热处理是有效的，并获得了与在STO衬底上类似的BKBO薄膜。在常温下沉积超导薄膜之前，在较高的衬底温度下沉积一段时间的BKBO缓冲层，可以在(100)MgO衬底上获得高质量的(100)BKBO薄膜。结性质的研究：我们研究了STO上结的性质，发现结的势垒中的电磁波速度比报道的其他材料结的速度小一个数量级，这表明了衬底的高介电常数的影响和低介电常数衬底的必要性。高频电路的研究：我们研究了超高频探测器基础实验的电路，包括结和天线等其他元件

项目成果

S. Imaeda: "Ba_<1-x>K_xBiO_3 Grain Boundary Junctions Prepared on SrTiO_3 Bicrystal Substrates" IEEE Trans. Appl. Supercond.5. 2208-2211 (1995)

S. Imaeda：“Ba_<1-x>K_xBiO_3 在 SrTiO_3 双晶基底上制备的晶界结”IEEE Trans。