Coupled motion of vortices between two superconducting films

• Main Author: 楊孟緯
• Other Authors: 洪連輝
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/78917945626333394885

碩士 === 國立彰化師範大學 === 物理學系 === 98 === The structure of the sample in this research is two superconducting films (Nb) and another insulating film (SiO2) between the two films. The external magnetic field was applied perpendicular to the film plane. Coupled motion of vortices was detected by measuring the voltage across the second film, in which no external current was applied. Voltage was induced by the motion of the vortices due to the passage of a DC current in the first film. The results are interpreted in terms of a vortex-slipping mechanism. The substrate is Si3N4.In this work, we defined electrodes by photo lithography and defined patterns by electron beam lithography. The superconducting Nb films were grown by DC magnetron sputtering and the SiO2 layer grown by AC magnetron sputtering. The thickness of Nb and SiO2 was measured by atomic force microscopy (AFM). MR measurements were carried out by a four-probe technique in a superconducting quantum interference device (SQUID) system with a temperature fluctuation within 3 mK. The external magnetic field was applied perpendicular to the plane of the films and transport current.