Significant pressure effects on iron-based superconductor families: Superconductivity, flux pinning and vortex dynamics
*Xiaolin Wang1,2

Pressure is well known to raise the Tc in Cu and Fe-based superconductor. My team has discovered that hydrostatic pressure can also significantly enhance the flux pinning and Jc in all the Fe-based superconductors [1]. I will review the recent research progress on high-pressure studies on the superconductivity, flux pinning, and vortex dynamics of iron-based superconductor families [2]. I will demonstrate that the hydrostatic pressure can not only significantly increase Tc, but also significantly enhance the irreversibility field, Hirr, as well as the critical current density, Jc, at both low and high fields in F- or Cl- doped and undoped FeSe0.5Te0.5, NaFe0.97Co0.03As, Ba0.6K0.4Fe2As2,Sr4V2O6Fe2As2 single crystals and polycrystalline bulks [1-9]. Our results show that hydrostatic pressure can induce more point defects responsible for the significantly enhanced Jc and flux pinning. Record high Jc values (∼2 × 105 A/cm2 at 4.2 K and 13 T, P = 1.1 GPa) were obtained for Sr0.6K0.4Fe2As2 tapes. Our findings indicate that there is still plenty of room to further improve the supercurrent carrying capability for both Fe-based superconductors.

This work is supported by Australian Research Council (ARC) through the ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET) and an ARC Professorial Future Fellowship project (FT130100778).

1) B. Shabbir, X.L. Wang, S.R. Ghorbani, C. Shekhar, S.X. Dou, O.N. Srivastava, Sci. Rep. 5 (2015) 8213
2) L.N. Sang, Z. Li, G.S. Yang, Z.J. Yue, J.X. Liu, C.B. Cai, T. Wu, S.X. Dou, Y.W. Ma, X.L. Wang, Materials Physics Today, 19 (2021)100414
3) B. Shabbir, X.L. Wang, S.R. Ghorbani, A.F. Wang, S. Dou, X.H. Chen, Sci. Rep. 5 (2015) 10606.
4) B. Shabbir, X.L. Wang, Y. Ma, S.X. Dou, S.S. Yan, L.M. Mei, Sci. Rep. 6 (2016) 23044.
5) B. Shabbir, H. Huang, C. Yao, Y.W. Ma, S.X. Dou, T.H. Johansen, H. Hosono, X.L. Wang, Physical Review Materials 1 (4) (2017): 044805.
6) Lina Sang, Pankaj Maheshwari, Jixing Liu, Zhi Li, Wenbin Qiu, Guangsai Yang, Chuanbing Cai, Shixue Dou, Veerpal Singh Awana, Xiaolin Wang, Scripta Mater. 171 (2019) 57e61.
7) J.X. Liu, S.N. Zhang, L.N. Sang, M. Li, W.Y. Zhao, Z. Li, Z.X. Cheng, L.Q. Liu, J.Q. Feng, C.S. Li, P.X. Zhang, S.X. Dou, L. Zhou, X.L. Wang, Scripta Mater. 169 (2019) 19e22
8) ] Lina Sang, Babar Shabbir, Pankaj Maheshwari, Wenbin Qiu, Zongqing Ma, Shixue Dou, Chuanbing Cai, V.P.S. Awana, Xiaolin Wang, Supercond. Sci. Technol. 31 (2) (2018): 025009
9) J.X. Liu, et al, ACS Applied Materials and Interfaces, 11(2019) 18825-18832.