Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Nov 3;14(21):6611.
doi: 10.3390/ma14216611.

Critical Current and Pinning Features of a CaKFe4As4 Polycrystalline Sample

Armando Galluzzi  1   2 , Antonio Leo  1   2 , Andrea Masi  3   4 , Francesca Varsano  3 , Angela Nigro  1   2 , Gaia Grimaldi  2 , Massimiliano Polichetti  1   2
Affiliations

Critical Current and Pinning Features of a CaKFe4As4 Polycrystalline Sample

Armando Galluzzi et al. Materials (Basel). .

Abstract

We analyze the magnetic behavior of a CaKFe4As4 polycrystalline sample fabricated by a mechanochemically assisted synthesis route. By means of DC magnetization (M) measurements as a function of the temperature (T) and DC magnetic field (H) we study its critical parameters and pinning features. The critical temperature Tc has been evaluated by M(T) curves performed in Zero Field Cooling-Field Cooling conditions. These curves show the presence of a little magnetic background for temperatures above Tc, as also confirmed by the hysteresis loops M(H). Starting from the M(H) curves, the critical current density Jc of the sample has been calculated as a function of the field at different temperatures in the framework of the Bean critical state model. The Jc(H) values are in line with the ones reported in the literature for this typology of samples. By analyzing the temperature dependence of the critical current density Jc(T) at different magnetic fields, it has been found that the sample is characterized by a strong type pinning regime. This sample peculiarity can open perspectives for future improvement in the fabrication of this material.

Keywords: 1144 IBS family; DC magnetic properties; iron-based superconductors; magnetism and superconductivity; pinning force analysis; pinning properties.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Magnetization versus temperature M(T) measured in ZFC-FC conditions at H = 0.01 T. Inset: Tc is indicated by a red arrow.
Figure 2
Figure 2
Magnetization versus field at different temperatures below Tc.
Figure 3
Figure 3
Magnetic hysteresis loop at T = 40 K.
Figure 4
Figure 4
Jc versus field at different temperatures.
Figure 5
Figure 5
Temperature dependence of Jc at different applied magnetic fields fitted with strong pinning model (black solid line).
Figure 6
Figure 6
Jc at T = 0 K as a function of the magnetic field has been reported together with the fit with the Kim critical state model (red solid line).
Figure 7
Figure 7
Normalized pinning force density as a function of the reduced magnetic field h = H/Hirr at T = 30 K fitted with Equation (4). Fit details are reported in the text.
See this image and copyright information in PMC

References

    1. Iyo A., Kawashima K., Kinjo T., Nishio T., Ishida S., Fujihisa H., Gotoh Y., Kihou K., Eisaki H., Yoshida Y. New-Structure-Type Fe-Based Superconductors: CaAFe4As4 (A = K, Rb, Cs) and SrAFe4As4 (A = Rb, Cs) J. Am. Chem. Soc. 2016;138:3410–3415. doi: 10.1021/jacs.5b12571. - DOI - PubMed
    1. Yuan H.Q., Singleton J., Balakirev F.F., Baily S.A., Chen G.F., Luo J.L., Wang N.L. Nearly isotropic superconductivity in (Ba,K)Fe2As2. Nature. 2009;457:565–568. doi: 10.1038/nature07676. - DOI - PubMed
    1. Yamamoto A., Jaroszynski J., Tarantini C., Balicas L., Jiang J., Gurevich A., Larbalestier D.C., Jin R., Sefat A.S., Mcguire M.A., et al. Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide. Cit. Appl. Phys. Lett. 2009;94:062511. doi: 10.1063/1.3081455. - DOI
    1. Grimaldi G., Leo A., Martucciello N., Braccini V., Bellingeri E., Ferdeghini C., Galluzzi A., Polichetti M., Nigro A., Villegier J.-C., et al. Weak or Strong Anisotropy in Fe(Se,Te) Superconducting Thin Films Made of Layered Iron-Based Material? IEEE Trans. Appl. Supercond. 2019;29:1–4. doi: 10.1109/TASC.2019.2895744. - DOI
    1. Leo A., Braccini V., Bellingeri E., Ferdeghini C., Galluzzi A., Polichetti M., Nigro A., Pace S., Grimaldi G. Anisotropy effects on the quenching current of Fe(Se,Te) Thin Films. IEEE Trans. Appl. Supercond. 2018;28:8234633. doi: 10.1109/TASC.2017.2786460. - DOI