Hydrostatic pressure effect on superconductivity and vortex pinning mechanism of Sr(Fe0.88Co0.12)2As2 single crystal
Abstract
The external pressure effect on superconducting transition temperature (Tc) was investigated by dc magnetic and electrical resistivity studies for Sr(Fe0.88Co0.12)2As2 single crystal down to 2 K. The observed large diamagnetic signal and zero resistance clearly indicate bulk superconductivity with sharp Tc of ∼16.5 K (0 GPa). Onset of Tc is suppressed monotonically down to 5.2 K under pressure up to 2.8 GPa. The evaluation of Tc was observed by the application of magnetic fields and critical field was estimated to be rather high of about 10 T. These observed results reveal a large vortex region that replicates high anisotropy of the systems. The observed coherence length ξGL(0) was estimated to be ∼57 Å. We evaluated the thermally activated flux flow activation energy (U0) at 100 K using the Arrhenius equation. Finally, the temperature and pressure dependent critical current density Jc(T) and reduced flux pinning force (fp) were analyzed by collective pinning model with different magnetic fields.
- Publication:
-
Physica C Superconductivity
- Pub Date:
- August 2019
- DOI:
- 10.1016/j.physc.2019.04.003
- Bibcode:
- 2019PhyC..563...22S
- Keywords:
-
- Superconductivity;
- Activation energy gap;
- Critical current density;
- Vortex pinning