Institute of High Pressure Physics

Magnetic or nonmagnetic substitution generally plays a significant role on the properties of a superconductor. It can induce disorder into the crystal, produce the impurity scattering, and cause a Cooper pairbreaking effect. Recently, Dr. Singh's research team from NL-6 has published a research paper that explores the non-magnetic Cu impurity effect on the high T_c iron-based superconductor through various types of measurements and analysis, including DFT calculations. This study concludes that the substitution of Cu in the superconducting FeAs layer results in the enlargement of the lattice volume and is a source of strong disorder scattering that leads to the suppression of superconducting properties and the emergence of a metal-to-insulator transition.

This paper is published by M. Azam, M. Manasa, T. Zajarniuk, T. Palasyuk, R. Diduszko, T. Cetner, A. Morawski, C. Jastrzebski, M. Wierzbicki, A. Wiśniewski, Shiv J. Singh entitled “Copper doping effects on the superconducting properties of Sm-based oxypnictides” J. Am. Ceram. Soc. 2024;1–15. https://doi.org/10.1111/jace.19936

Fig. The variation of (A) the onset transition temperature (T_c^onset), (B) the transition width (ΔT = T_c^onset – T_c^offset), and (C) Residual resistivity ratio (RRR = ρ_{300 K}/ρ_{60 K}) of SmFe_1−xCu_xAsO_0.8F_0.2 with the nominal doping contents (x) compared to the reported Ni and Ru doping contents.