Low-field vortex dynamics in various high-𝑇c thin films

Pramana

K V Rao¹  Johan J Ã…kerman¹ 

[1] Department of Materials Science – Tmfy-MSE, Royal Institute of Technology, S-100 44 Stockholm, Sweden$$

关键词: Vortex dynamics;    flux creep;    high temperature superconductor;    thin film;    ac susceptibility.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We present a novel ac susceptibility technique for the study of vortex creep in superconducting thin films. With this technique we study the dynamics of dilute vortices in 𝑐-axis oriented Y-123, Hg-1212, and Tl-1212 thin films, as well as 𝑎-axis oriented Hg-1212 thin films. Results on the Hg-1212 and Tl-1212 thin films indicate that dislocation-mediated plastic flux creep of single vortices dominates at low temperatures and fields. As the temperature (or the field) is increased, the increasing vortex–vortex interactions promote a collective behavior, which can be characterized by elastic creep with a non-zero 𝜇 exponent. Also, in some of these samples effects of thermally assisted quantum creep are visible up to 45 K in some of these samples. In Y-123 thin films, creep is found to be collective down to the lowest temperatures and fields investigated, while the quantum creep persists only up to 10–11 K.

【 授权许可】

Unknown