Suppression of flux avalanches in YBCO superconducting thin films by coating metal investigated using magneto-optical imaging  

作　　者：Qianting Ran Ze Jing Lei Shen Jun Zhou Cong Liu Zhiwei Zhang Xingyi Zhang 

机构地区：[1]Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China,Lanzhou University,Lanzhou,Gansu 730000,PR China [2]Department of Mechanics and Engineering Sciences,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,Gansu 730000,PR China [3]Institute of Extreme Mechanics and School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,PR China

出　　处：《Superconductivity》2024年第3期4-13,共10页超导（英文）

基　　金：National Natural Science Foundation of China(No.12325205,No.12232005,U2241267,12272155);Major Scientific and Technological Special Project of Gansu Province(23ZDKA0009);Natural Science Foundation of Gansu Province of China(No.23JRRA1118).

摘　　要：Flux avalanches,prevalently existing in superconducting thin films,can cause catastrophic breakdowns of electromagnetic properties and even irreversible damage to superconducting materials.Metal coating is an effective way to suppress the flux avalanches in superconducting thin films.Nevertheless,it is difficult to reveal the suppression mechanisms due to the challenge of effectively separating the simultaneous eddy currents and heat exchange in the metal coating.In this work,the eddy currents and heat exchange in the Ag metal coating are separated by setting a thermal insulation layer,and its inhibiting effect on the flux avalanches of the YBCO superconducting thin films is elucidated.The results indicate that eddy currents play an important part in suppressing magnetic flux avalanches,and their effect strengthens with increasing Ag thickness.Meanwhile,employing the double-exposure method,the flux avalanche velocity of YBCO superconducting thin films was measured,revealing a significant decrease in the magnetic flux avalanche velocity due to suppression by eddy currents.Moreover,a theoretical model was established to investigate the influence of eddy currents on the motion of a single vortex,and the calculated results showed good agreement with the experiments.These findings provide a better understanding of the flux avalanches and their suppression in YBCO superconducting thin films.

关 键 词：YBCO superconducting thin films Flux avalanches Metal coating Eddy currents Double-exposure method 

分 类 号：TG14[一般工业技术—材料科学与工程]