Supplementary Material
Giant increase of critical current density and vortex pinning in
Mn doped KxFe2-ySe2 single crystals
Mingtao Li1,2, La Chen1,a), Wen-Long You3, Junyi Ge4, Jincang
Zhang1,2,b)
1
Department of Physics, Shanghai University, Shanghai 200444, China
2
Materials Genome Institute, Shanghai University, Shanghai 200444, China
3
College of Physics, Optoelectronics and Energy, Soochow University, Suzhou
215006, China
4
INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan
200D, B-3001 Leuven, Belgium
To study the temperature evolution of 𝐽𝑐 (𝜇0 𝐻) and vortex pinning mechanism, we
measured the isothermal MHLs at different temperatures. The typical MHLs for S2
sample are shown in Fig. S1(a) and S1(b), and 𝐽𝑐 (𝜇0 𝐻) curves are plotted in Fig.
S1(c) and S1(d). For 𝐻 ∥ 𝑐, the MHLs exhibit high symmetric feature with respect to
𝜇0 𝐻. Similar to high quality KxFe2-ySe2 single crystal,27 the ZFCP of the MHLs is
absent below 𝑇=15 K. It was pointed out by Liu et al that the absence of ZFCP is a
sample-dependent phenomenon,14 whose occurrence depends on the uniform and
contiguous distribution of the superconducting phase. Contrary to other “122”
systems,4,5 the SMP effect disappears quickly for S2/S3 samples with increasing
temperature. As the temperature goes up to 27 K, the opening area of MHLs shrinks
gradually which evidences a reduction of capability of carrying supercurrent towards
high magnetic field. Furthermore, the calculated 𝐽𝑐 (𝜇0 𝐻) exceeds 104 A/cm2 for 𝐻 ∥
𝑐 while 103 A/cm2 for 𝐻 ∥ 𝑎𝑏 below 11 K, and 𝐽𝑐 has a weak field dependence.
a) Present address: Peter Grünberg Institute (PGI-8), Forchungszentrum Jülich,
D-52425 Jülich, Germany
b) Corresponding author, E-mail: jczhang@staff.shu.edu.cn
FIG. S1.
REFERENCES
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H. Yang, H. Q. Luo, Z. S. Wang and H. H. Wen, Appl. Phys. Lett. 93, 142506 (2008).
5
D. L. Sun, Y. Liu, C. T. Lin, Phys. Rev. B 80, 144515 (2009).
14
Y. Liu, Q. Xing, K. W. Dennis, R. W. McCallum, T. A. Lograsso, Phys. Rev. B 86,
144507 (2012).
27
B. Shen, B. Zeng, G. F. Chen, J. B. He, D. M. Wang, H. Yang and H. H. Wen,
Europhys. Lett. 96, 37010 (2011).
Figure captions_Mingtao Li et al.,
FIG. S1. (a) and (b) show the isothermal MHLs at various temperatures for S2 sample
with 𝐻 ∥ 𝑐 and 𝐻 ∥ 𝑎𝑏, respectively. Shown in (c) and (d) are the corresponding
magnetic field dependence of critical current density.