Superconductivity in SmFe1-xMxAsO (M = Co, Rh, Ir)

Abstract

In this paper we report the comparative study of superconductivity by 3d (Co), 4d (Rh), 5d (Ir) element doping in SmFeAsO. X-ray diffraction patterns indicate that the material has formed the ZrCuSiAs-type structure with a space group P4/nmm. It is found that the antiferromagnetic spin-density-wave (SDW) order in the parent compounds is rapidly suppressed by Co, Rh, and Ir doping, and superconductivity emerges. The diamagnetism, consistent with the R-T data, conforms to the bulk superconductivity in our SmFe1-xMxAsO (M=Co, Rh, Ir) samples. Co, Rh and Ir locate in the same column in the periodic table of the elements but have different electronic band structure, so a comparative study would add more ingredients to the underlying physics of iron-based superconductors.