高Tc超导GdBa_2Cu_3O_(7-δ)薄膜双晶晶界结及双晶结光探测器  

High Tc Superconducting GdBa_2Cu_3O_(7-δ) Thin Film Bicrystal Junctions and Optical Detectors

作　　者：万云[1] 万发宝 平一梅[1] 王瑞兰[2] 姚久胜[2] 李宏成[2] 

机构地区：[1]西北大学物理系,西安710069 [2]中国科学院物理研究所国家超导实验室,北京100080

出　　处：《低温与超导》2000年第2期26-29,共4页Cryogenics and Superconductivity

摘　　要：在晶界夹角分别为 2 4°,3 2°的 YSZ双晶基片上 ,制备了高 Tc Gd Ba2 Cu3O7-δ双晶超导薄膜 ,采用光刻技术在晶界上刻出了两种不同尺寸的双晶晶界结 ,在液氮温度下观测了结的直流 I-V特性 ,用 1 0 GHz微波辐照双晶结结区 ,观察到了结临界电流的压缩和 Shapiro台阶 ,表明双晶结具有约瑟夫逊弱连接行为。用上述双晶结进行光探测 ,用波长为 0 .63 2 8μm的 He-Ne激光器辐照结区 ,系统的观测了其光响应特性 ,结果如下 :噪声等效功率 NEP =1 .9× 1 0 - 1 3W,归一化探测率 D*=5.3× 1 0 9cm Hz12 W- 1 ,响应率 Rv =4 .2× 1 0 7V/W,响应时间 τ<6.3 5× 1 0 -The high Tc superconducting GdBa 2Cu 3O 7-δ thin film bicrystal had been fabricated on YSZ bicrystal substrates, the misorientation angle of bicrystal boundary are 24° and 32° respectively. Two kinds of bicrystal grain boundary junctions were fabricated using general photolithgraphy technique on the grain boundary. The I-V characteristics and the Shapiro steps were measured under direct current and with 10GHz microwave irradiation respectively at 77K. The Josephson weak link characteristics were shown by experimental results of our bicrystal junction. The light detection was performed with the bicrystal junction. The light response characteristics of junction for He-Ne laser with 0.6328μm wave length were measured. The results are as follows:NE=1.9×10 -13 W,D *=5.3×10 9cmHz 1/2 W -1 ,R v=4.2×10 7V/W,τ<6.35×10 -7 s.

关 键 词：高Tc超导薄膜 双晶晶界结 光探测器 

分 类 号：O511[理学—低温物理]