Vortex activation energy in the AC magnetic response of superconducting YBa2Cu3O7 thin films with complex pinning structures

I. Ivan, A. M. Ionescu, D. Miu, P. Mele, L. Miu

研究成果: Article査読

3 被引用数 (Scopus)

抄録

The vortex activation energy U AC in the AC magnetic response of superconductors exhibits a logarithmic variation with the screening current density J (regardless of the pinning structure details), and takes surprisingly high values in the vicinity of the DC irreversibility line, especially at low external DC magnetic fields, as often reported. This is essentially different from the behaviour of the vortex-creep activation energy at long relaxation time scales in DC magnetic measurements, and is not completely understood. We investigated the DC relaxation and the AC response for YBa2Cu3O7 films containing nanorods and nanoparticles, with the DC and AC fields oriented perpendicular to the film surface. It is shown that the large U AC values in the vicinity of the DC irreversibility line, where the critical-state-related AC signal occurs, are generated by a non-diffusive vortex motion during the AC cycle, with the mean vortex hopping length longer than the average distance between the pinning centres. In these conditions, the smearing of the vortex pinning potential by thermally induced vortex fluctuations is weak, and U AC mainly results from the strong influence of the pinning-enhanced viscous drag on the vortex hopping process. The logarithmic U AC(J) dependence is consistent with a high U AC.

本文言語English
論文番号095013
ジャーナルSuperconductor Science and Technology
29
9
DOI
出版ステータスPublished - 2016 8 8
外部発表はい

ASJC Scopus subject areas

  • セラミックおよび複合材料
  • 凝縮系物理学
  • 金属および合金
  • 電子工学および電気工学
  • 材料化学

フィンガープリント

「Vortex activation energy in the AC magnetic response of superconducting YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub> thin films with complex pinning structures」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル