Superconductivity at 35.5 K in K-Doped CaFe2As2

• Published in: Journal of superconductivity and novel magnetism Vol. 26; no. 6; pp. 2121 - 2124
• Main Authors: Wang, D. M., Shangguan, X. C., He, J. B., Zhao, L. X., Long, Y. J., Wang, P. P., Wang, L.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.06.2013; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical resistivity; Exact sciences and technology; Letter; Magnetic fields; Magnetic Materials; Magnetism; Mathematical analysis; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconducting materials (excluding high-tc compounds); Superconductivity; Superconductors; Synthesis; Temperature dependence; Pnictides; Hole-doped; Critical fields; Substitution; Electrical conductivity; Volume fraction; Hole density; Superconducting transitions; Doping; Superconductivity; Magnetic field effects; Iron; Critical field; Superconductors; Calcium Iron Arsenides Mixed; Anisotropy; Iron based arsenide
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-013-2169-5

We report the successful synthesis of a new iron-based 122-family superconductor K-doped CaFe 2 As 2 . The temperature dependence of resistivity shows a sharp superconducting transition at ∼35.5 K, which is the highest value among the hole-doped CaFe 2 As 2 superconductors reported so far. A superconducting volume fraction of ∼100 % at 2.5 K is calculated from the diamagnetic signal, which confirms the bulk superconductivity characteristic of the sample. The measurement of resistivity under different magnetic fields gives very large upper critical fields and a small anisotropy parameter, which are consistent with that of the other 122 superconductors.