Intrinsic and extrinsic pinning in NdFeAs(O,F): vortex trapping and lock-in by the layered structure
| Autor: | Sein Schmidt, Hiroshi Ikuta, David C. Larbalestier, N. Sumiya, Fritz Kurth, Chiara Tarantini, Kazumasa Iida, Jens Haenisch, Takafumi Hatano, Jan Jaroszynski, Paul Seidel, B. Holzapfel, M. Chihara |
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| Rok vydání: | 2016 |
| Předmět: |
Shearing (physics)
Superconductivity Physics Multidisciplinary Condensed matter physics Field (physics) Condensed Matter - Superconductivity FOS: Physical sciences 02 engineering and technology Crystal structure Trapping 021001 nanoscience & nanotechnology 01 natural sciences Article 3. Good health Vortex Superconductivity (cond-mat.supr-con) Planar Condensed Matter::Superconductivity 0103 physical sciences ddc:530 010306 general physics 0210 nano-technology Anisotropy |
| Zdroj: | Scientific Reports Scientific reports, 6, 36047 |
| ISSN: | 2045-2322 |
| DOI: | 10.48550/arxiv.1610.08486 |
| Popis: | The Fe-based superconductors (FBS) present a large variety of compounds whose properties are affected to different extents by their crystal structures. Amongst them, the $\it{RE}$FeAs(O,F) ($\it{RE}$1111, where $\it{RE}$ is a rare earth element) is the family with the highest critical temperature $T_c$ but also with a large anisotropy and Josephson vortices as demonstrated in the flux-flow regime in Sm1111 ($T_c$ $\sim$ 55 K). Here we focus our attention on the pinning properties of the lower-$T_c$ Nd1111 in the flux-creep regime. We demonstrate that for H//c critical current density $J_c$ at high temperatures is dominated by point-defect pinning centres, whereas at low temperatures surface pinning by planar defects parallel to the $\it{c}$-axis and vortex shearing prevail. When the field approaches the $\it{ab}$-planes, two different regimes are observed at low temperatures as a consequence of the transition between 3D-Abrikosov and 2D-Josephson vortices: one is determined by the formation of a vortex staircase structure and one by lock-in of the vortices parallel to the layers. This is the first study on FBS showing this behaviour in a full temperature, field, and angular range and it demonstrates that, despite the lower $T_c$ and anisotropy of Nd1111 with respect to Sm1111, this compound is substantially affected by intrinsic pinning generating a strong $\it{ab}$-peak in $J_c$. Comment: Final version available on Scientific Reports (Open access) |
| Databáze: | OpenAIRE |
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